Been a while since I gave this speech, so bear with me.
If it's a milled receiver MAK-90 you need to have 4 US parts, if stamped 5 US parts, from the following list for the AK (+1 on all parts counts if you are adding a muzzle device).
For an AK the simplest things to swap out are:
Fire control group (Hammer, trigger, sear) - 3 parts
Furniture (stock, pistol grip, upper/lower handguards) - 3 parts
Gas piston - 1 part
Swapping other parts out for American made (reciever, trunion, barrel, bolt, carrier, are also qualifying parts) is pretty difficult.
So, if you plan on making the rifle a folder, you currently have zero US parts count (ignore the brake).
If you want to add a non-US underfolder, I suggest you get a new FCG from RSA (3 parts), the pistol grip you like (1 part), and a set of US made handguards (1 part). You'll then be good to go woith your US made brake and a chinese/russian/romanian/etc folding stock.
This is my MAK-90 with a folder: