Please help identify my 1940's (?) Tandem Bicycle

It looks similar to 1936 BSA T64. I am not an expert, obviously, but according to the pics you gave and the pics I found of the BSA at the time, that looks like the match. The only other one I found was made in 1897 and then after finding this one, I could not find the one from 1897 anymore. But the frame looked like the one from 1897 and the gears and tires looked like the 1936

This is a little crazy but here goes.

I think it's the front of a Hawthorn men's bike

With a Hawthorne ladies bike wielded on for the back half

The rear stays of the men's bike are removed. The head tube on the ladies bike is removed, the top and bottom tubes are wielded to the seat tube on the men's bike. Both bikes have the correct skip tooth front sprockets.

The connecting tube between the "top" tube and the "bottom" tube on the ladies bike is no longer parallel with the ground on the tandem because the seat tube angle is not the same as the head tube angle.

An extra tube is wielded between the bottom brackets on the two bikes.

The ladies bike is listed as being a 1941. The men's bike is listed as "pre-war".

Here is a good discussion on dating a Hawthorn bike.

Hawthorne used three different chain rings on their full size prewar balloon models, the ?snowflake? the ?speed-comet? and the ?torque-star? (my names). The torque-star chain ring didn?t appear until 1940 so if it is original to your bike that would date it to 1940-1942.