There aren't going to be many "pristine" examples. The vast, vast, vast majority are going to be mix-masters Most have been around since WWII so they've been re-barreled probably at least once, any parts that broke or were damaged got swapped out with whatever parts were on-hand (PLL) or came in through the supply system with no regard for manufacture.
Now my AD unit was the extreme in use and abuse of our 1911's (MP's draw and carry their weapons every day), so they got the crap beat out of them. Plus we had to qualify every 90 days, so we shot the *expletive deleted*it out of them. I know our armorer was always working on out 1911's to keep up. We were always worried that if we Private Joe one of the spares we carried, and he had to shoot someone/something, the first question that was going to asked was "When did you last qualify with that weapon ?" We knew that "I didn't, that's one of the company's spares" was going to be a really bad answer,
We frequently had the CQ help during the day in the arms room, doing the simple things, like parts swaps/replacements just to keep up with all the work on all the weapons (160-1911's, 70-M16A2's, 45-M203's, 45-M60's and 4-M2's)