I stll have the first 1911A1 I ever bought, back in 1965. I think I paid about $150 for it, it's a Colt, fully GI with no "tuning" done to it, and I'll stack it up against any plastic gun out there.
I also own an Ithaca WWII 1911A1, a Colt 1911 (born on date Dec 1912), a Remington Rand WWII 1911A1 rebuilt at the Augusta Arsenal, a Norinco 1911, and last fall I bought one of the new Remington Talo pistols. The only thing I've changed out in any of these pistols is the recoil springs in a couple, and I did replace the stainless barrel bushing in the Talo to a pakerized bushing. I just couldn't stand that bright end.
Point of this is, they are excellent guns just as JMB designed them, and don't need a lot of tuning to be accurate. I think the military 1911 pistols are far more accurate than most of the new pistols being pushed today. They won't generally shoot a quarter inch group at 50 yards, but neither will I these days.