Ah man, that sounds sweet! My father bought his as a Texas car, so no rust it was a 390 with a auto, around the early 90s, stripped it down, repainted it from the factory color (gold) to a metallic blue. He converted the car from a auto to a manual and then took out the 390 and rebuilt it. Around 2000-ish he started to take it apart again, and in 2003-ish he repainted it, in our one-car garage, fire engine red, one piece at a time. He would take a piece, say the hood, sand it, prime it, sand it, prime it, and then he painted it. There are no dust spots in the paint or clear. Then around 2005-ish the oil pump gave out and basically ruined the engine (crank, pistons, and a bunch other stuff is shot) so we tore that engine out and got a Javelin donor car for a 360, stripped that down and rebuilt that, and now that engine is starting to go too. Right now we got another 360, stripped that down, had it cleaned up by a machinist shop, bored .30 over, we got new piston and rings, new crank, cam, all the good stuff. Pretty soon we'll have the 360 (the old one) out of the car and have the .30 over 360 in the car. The car also need a new clutch, it's a very heavy clutch.
Just like yours, no power anything, drums all around... That really sucks, you sell it and then realize you didn't have to sell it all along! Hope it went to good hands... I think this is my dad's 6th AMX, not sure... If you look around on EvilBay, there's always a couple in the 7k-12k range that could use a little work... And I believe you, these are fast cars. AMX are pretty quick cars, especially for what they had and the short time they were in production.
It's a model, believe it or not!