Years ago when you could buy the old military surplus 10911s cheap, I would tearoom down, peen the receiver rails, squeeze the slide a little, and coat both with a little valve grinding compound. Put the receiver in a padded vice, and tap the slide on. After working it back and forth ir was a perfect fit. If I didn't have a new barrel, I'd smack the old barrel bushing with a hammer, put a new link on the barrel, throat the barrel so it would feed wadcutters, replace the slide spring, and do a trigger job.
All that tightened the pistol up, and it would shoot closer than most were capable of holding it.
New sights were a pretty easy chore depending on what they wanted.
The pistols had to be tuned, for reliability after all that, but the point is "tolerances" were tighter, and accuracy is dependent on the pistol going into battery and cycling the same everytime.
I've seen stock Model 10 Smiths out shoot a Gold Cup National Match.
The single action in the 1911 when done right, combined with close tolerances, and a good tune are why they a good match pistol. If a match pistol is what you want.