Minecraft: How can we repopulate a VANILLA world with MODDED ores?

I’m currently stuck in the process of trying to finalize a modded world in Minecraft. I need to repopulate ALREADY CREATED chunks with ores from mods.

For more context:

• We’re trying to use a 1.7.10 Earth map. We found a couple, all of which look fine and okay.
• We’re also trying to use a 1.7.10 modpack
  that is personalized to fit our Minecraft experience. It includes
  simpler mods like ArchimedesShips and Flans as well as
  worldgen-spawning stuff like Thermal Foundation, IC2, Tinker’s
  Construct, and Pam’s HarvestCraft

Particularly, the combination of the above premises is something I can’t do, but are exactly what I need to do. I’m fairly familiar with MCEdit, MultiMC, COFHCore, WorldEdit, etc., so any combination of such to produce the modded ores would be the appreciated. The closest I’ve gotten to such a world was using COFHCore to regen ores which kinda did it. Through some config file tampering I got Thermal Foundation ores to generate in the Vanilla Earth map. However, two problems arose: ONLY thermal foundation ores were regen-ing into the vanilla map, and it simply took too long and by the time I checked in (2 hours into regening) on how much has regened, only a part of India got all the cool new ores.

I know this might seem impossible, but I got close to what I was hoping for, so I know it’s possible. I’m hoping that someone out there might know the answer or at least another step to finding it. This is a really cool idea and I would appreciate any help. Thank you.

NOTE All help is appreciated, but please don’t ask me to delete chunks in MCEdit. I understand that I can delete chunks to get new chunks with modded stuff, but that’s not what I’m looking for.