I have a couple of 1911's. I know how to reassemble without scratching, but my Combat Elite does have a very slight scratch from one time I was reassembling.
I shoot my guns a lot, and to me, the "idiot scratch" is not a big deal.
As for a gun that was actually issued to the armed forces, well, who knows the history. There may have been a time when the pristine finish of a Government issued sidearm was that last thing the soldier cared about!
I try not to abuse my guns, but they will get scratches, dings, and so on. Guns are nice to look at, but they are more fun to handle and shoot often.