Is there anything in Marvel canon comparing the power levels/abilities between Johnny Storm (The Human Torch) and Jim Hammond (the original Torch)?

Let's go over the categories specified in the official power charts one-by-one.

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Intelligence:

Jim Hammond and Johnny Storm's power charts in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rate their intelligence at 2. The first issue of that volume defines that specific rating thusly:

2 = Normal

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Strength:

Hammond's power chart in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rates his strength at 3, which is defined as:

3 = Peak human: able to lift over twice own body weight, up to 800 lbs.

Hammond's entry in Official Handbook of the Marvel Universe Vol 3 #4 states the following:

Strength level: The original Human Torch possesses the normal human strength of a man in his middle twenties of the Torch's height and build who engages in moderate regular exercise.

Hammond's height is listed as 6'3" and his weight as 300 pounds.

Storm's power chart in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rates his strength at 2, which is defined as:

2 = Normal: able to lift over own body weight, up to twice own body weight.

Storm's entry in Official Handbook of the Marvel Universe Vol 2 #6 states the following:

The Human Torch possesses the normal human strength of a man of his age, height, and build who engages in moderate regular exercise.

Storm's height is listed as 5'10" and his weight as 170 pounds.

Given that Hammond is significantly taller and heavier than Storm, this would suggest that he has a noticeable strength advantage, which is consistent with his slightly higher rating in the power charts.

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Speed:

Hammond's power chart in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rates his speed at 3, which is defined as:

3 = Subsonic Superhuman: peak velocity below Mach-1 (approximately 760 miles per hour)

The text in his entry specifies that he can...

fly at speeds of at least 350 mph

Storm's power chart in the same issue rates his speed at 5, which is defined as:

5 = Supersonic: peak velocity between Mach-2 to Orbital Velocity (approximately 17,000 mph)

Oddly though, the text in his entry says...

By forming a jet from his feet, directed behind him, he can achieve speeds up to at least 140 miles per hour.

... which seems to contradict his higher rating in this category.

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Durability:

Hammond's power chart in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rates his durability at 3, which is defined as:

3 = Enhanced

The text in his entry states the following:

A near-perfect human simulation, Torch had the capacity for creative intelligence and unlimited self-motivated activity, and his physiology allowed him to eat, sleep and otherwise engage in human activity; he was even susceptible to poison, although his unique nature customarily burned poison out of his system before he could be fully incapacitated. He did not age and was immune to the effects of fire, extreme heat and electrocution but could be injured by bullets, knives and other conventional projectiles.

Storm's power chart in the same issue gives him two ratings for durability. In general durability, he's rated at 2, which is defined as:

2 = Normal

In durability against fire/heat specifically, he's rated at 6, which is defined as:

6 = Superhuman

The text in his entry states the following:

Human Torch is unaffected by heat and flames, including his own, even when part of him is aflame because his body constantly absorbs the heat, preventing his body from catching fire, and later expends the buildup through flight or flame blasts. His flesh cannot be scalded or burned by any heat source whose level is below that of his maximum output. While he can withstand extreme levels of heat, he is apparently unable to withstand the levels found near the center of the Earth's core.

When you read the accompanying text for both characters, it suggests that Hammond is just as durable against fire/heat as Storm, and should've been given a secondary rating of 6 as well.

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Energy Projection:

Their power charts in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rate them both at 5 in energy projection, which is defined as:

5 = Long range, long duration, single energy type

Hammond's entry in Official Handbook of the Marvel Universe Vol 3 #4 states the following:

Originally, when aflame, the Human Torch is enveloped by a low intensity flame of low level plasma (reddish, approximately 780° Farenheit) which ranges from 1 to 5 inches from his body. He can, however, generate much higher levels of heat and flame about himself. The Torch refers to the highest, hottest levels of plasma that he can create as his "nova flame." The exact temperatures that his "nova flame" can attain are unknown.

At an average rate of expenditure of energy, the Torch can stay aflame for about 16.8 hours. He cannot maintain his "nova flame" for as long a time as he can maintain his ordinary, low-intensity flame. The Torch can release all of his body's stored energy in one intense, omnidirectional "nova-burst," which can reach about 1,000,000° F and which is similar to the heat-pulse of a nuclear warhead detonation, with an area of total devastation of about 900 feet in diameter. This violent discharge uses his entire reserve of energy (except that necessary to maintain his artificial life) at once, entirely exhausting his flame power. He generally requires at least 12 hours to recover entirely from such a feat.

The Human Torch can generate shapes composed of fire from any point on his body. (He usually employs his hands to "sculpt" the flames.) He can form fire into long streams, spheres, or even more complex shapes like letters in skywriting. These flame-objects will only retain their shapes as long as he concentrates upon them. The objects will only burn for about 3 minutes before expiring unless the Torch continues to infuse them with energy. The temperature of these fiery projections is generally around 2,800° F (near the melting point of iron).

Storm's entry in Official Handbook of the Marvel Universe Vol 2 #6 states the following:

Ordinarily, when aflame, the Human Torch is enveloped by a low intensity flame of low level plasma (reddish, approximately 780 Farenheit), which ranges from 1 to 5 inches from his body. He can, however, generate much higher levels of heat and flame about himself. The Torch refers to his highest, hottest levels of plasma that he can create as his "nova flame." The exact temperatures that his "nova flame" can attain are not known.

At an average rate of expenditure of energy, the Torch can stay aflame for about 16.8 hours. In his younger days, he could only maintain his flame for much briefer periods, and sometimes exhausted it while in combat. He cannot maintain his "nova flame" for as long as he can maintain his ordinary, low-intensity flame. The Torch can release all of his body's stored energy in one intense, omnidirectional "nova-burst," which can reach about 1,000,000 F, and which is similar to the heat-pulse of a nuclear warhead detonation, with an area of total devastation of about 900 feet in diameter. (The Torch has claimed that he can destroy a small moon with his nova-burst.) This violent discharge uses his entire reserve of energy (except for that necessary to keep him alive) at once, entirely exhausting his flame power. He generally requires at least 12 hours to recover entirely from such a feat.

The Human Torch can generate shapes composed of fire from any point on his body. (He usually employs his hands to "sculpt" the flames.) He can form fire into long streams, spheres, or even more complex shapes like letters in skywriting. These flame-objects will only retain their shapes as long as he concentrates upon them. The objects will only burn for about 3 minutes before expiring unless the Torch continues to infuse them with energy. The temperature of these fiery projections is generally around 2,800 F (near the melting point of iron).

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Fighting Skills:

Hammond's power chart in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rates his fighting skills at 4, which is defined as:

4 = Experienced fighter

Storm's power chart in Official Handbook of the Marvel Universe A-Z Vol 1 #5 rates his fighting skills at 3, which is defined as:

3 = Some training

The text in his entry notes that he is...

an excellent hand-to-hand combatant

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Taking everything in the round, these official bios suggest that Hammond is a bit physically stronger (due to being physically larger), a bit more durable against anything other than fire or heat, and bit more skilled at hand-to-hand combat. In regard to their actual flame powers though, they're rated as equals in most or all respects.

As you noted, Hammond did look superior when they fought in Fantastic Four Annual Vol 1 #4, however, he remarked that he had years more experience than Storm at the time, who was still a teenager near the start of his career. In Fantastic Four Vol 1 #388, the Fantastic Four fought their younger selves, and it was stated that they'd grown more powerful over the years, as their bodies had soaked up more cosmic radiation; the younger Storm's flame died out in the middle of their battle, while the older Storm was still good to go.

As such, although Hammond may still be marginally superior overall, since he retains certain physical advantages, if the two fought again now, it'd probably be a significantly closer contest than the one shown the old annual.