Added the following to my AO1911A1PKMA (Massachusetts compliant - series 80):
- hammer and grip safety from an ORM 1991A1 Colt Commander
- pachmayr arched mainspring housing
- high profile white dot sights from an AO Delux (staked front, dovetailed rear w/set screw)
- USGI slide stop, magazines and barrel bushing
- short serrated trigger from AO (came with long trigger)
- McCormick extended thumb safety
- pachmayr signature grips
- pachmayer magazine base pads
Everything fit perfectly. I put around 500 rounds through the pistol before the modifications and have never had a FTE or FTF. 100 rounds after the mods and no failures of any kind. Eats everything Winchester White box 230gr FMJ, Federal Hydra Shok 230gr JHP and Winchester 230gr JHP. I know AO doesn't have a great reputation with some of the more experienced 1911 shooters but I think I got good one.