I had a 1945 Ithaca with a Colt WWII slide, that had reportedly been rebuilt by an old Army Marksmanship Unit gunsmith. It had the works- tightened slide/lowered frame rails, 7-digit NM barrel, Micro sights, adjustable trigger, etc. It was exceptionally accurate, but had been shot just enough to loosen it to the point of being reliable. I put high fixed sights on it and replaced the match trigger with GI components... carried it on duty for a number of years.
I also used it during a week-long NRA LE Instructor school in 1991, where it digested 800 rounds of 200 grain SWC--in 100 degree heat--without choking even once. I have no idea how many rounds went through that gun before I got it, but during the time I owned it it burned at least 7-8 pounds of powder. The only thing I ever had to replace on it was an extractor.
“Nine-tenths of tactics are certain, and taught in books: but the irrational tenth is like the kingfisher flashing across the pool, and that is the test of generals. It can only be ensured by instinct, sharpened by thought practicing the stroke so often that at the crisis it is as natural as a reflex.” ~ T. E. Lawrence