I was wondering if there are any specific parts on the LC9 that are known to wear out early so that keeping a spare on hand is a good idea?
Other than springs I can’t think of any off hand. I would recommend you use a large plastic bag to contain it while working on it, specifically while removing any pins under spring tension. I’ve launched the hammer action pin into low earth orbit…never to be found. Mine has a rather low round count, perhaps 1.5k and still looks new inside.