Seems the early AR15A1 is hard to find for whatever reason. Wish I had kept mine and not traded it in on an A2; however, the A2 turned out to be a tack driver after I got done with it. Two-stage match trigger, SS Krieger barrel, match front and rear sights, floating handguard, added weight in butt stock to balance out.
I did find this A1 and it looks really nice.
Pre-Ban Colt AR-15 Model SP-1 Rifle Built 1974 - Colt AR 15 Rifles
Early "slap side" without brass deflector or forward assist. Makes me think I should buy it.