I got a Remington .45 auto back in the late 60's as part of an estate sale, along with a couple Walther PP's.
I mildly accurized the .45: I installed Micro adjustable sights, Micro barrel bushing, lapped it in, shaped and polished the feed ramp, enlarged the ejection port, tightened the slide, added a heavier recoil spring, changed the trigger and a couple of other things that slipped my CRS mind. I later gave it to good friend and he still shoots it. :)