A military AK63 kit in good condition is a very good find. FEG receivers are among the very best and are fully heat-treated. The question is, where did the receiver come from and what is the model number? In other words, you just don't find FEG receivers for sale unless they're the SA2000Ms with single-stack magazine wells. You can open it up for regular double stack. Maybe he took an SA85M out of it's receiver to make the AK63, but that's cutting off your nose to spite your face. Does the receiver already have the trunion and rear block in it? Are these the AK63 parts or from another rifle? So you need to find out what receiver he has and how much work, if any, will be needed to make it right for the AK63 kit.
The gas tube should be numbered to the gun, or at least should have an FEG-type number from another AK63. This is important, because the standard-length naked gas tube is the only part of the kit that's different and very hard to find. I had to make one out of a standard Bulgarian gas tube for my AK63 look-alike. The vented steel forearm and pistol grip is what they later used for the AMD65, and these are plentiful. The buttstock is hard to find and should match the pistol grip in a muted teak color. Rifle finish on a 'virgin' kit would be a semi-flat black, and FEG always finished the bolt carriers in black too.
Then you have the requirements of 922r, so you'll need some USA parts, like a Tapco G2 FCG, USA-made muzzle nut and a magazine with USA-made follower and floorplate - KVAR has the mags.