Originally Posted by Twin Wasp

Or you can can go to the FSIMS guidance for the FAA and try to decode it.

FSIMS Document Viewer

What it says is if you don't currently hold a FAA certificate they will issue you a private with your type ratings limited to VFR ONLY under 61.75. If you then get a normal commercial or ATP and can show the training for your foreign type was conducted by the holder of a FAA CFI they'll move your type ratings over to your normal certificate. But since you say you have an ATP you can't go back and get a 61.75. So you're stuck doing the normal GS, sims and checkride. The only question is how much GS and how many sims. That's all controlled by the 142 school's training program and what courses they have approved by the FAA.