FWIW, with dedicated care & maintenance I've seen other SIG pistols go high round counts with minimal visible wear. We had an agency P229-357 come back with a reported 104,000 rounds through it and the head technical expert at SIG claimed it was impossible for the gun to be that used. But the agent who'd been issued a gun was (1) a close personal friend of mine and (2) religious about keeping a very detailed shooting log. He was able to prove the round count claim, though only after being calmed down when he found out, essentially, that SIG called him a liar.

Having said that, I'm surprised to hear that the trigger return, decocker, and hammer rebound springs are all original on the OP's gun. That's an unrealistically high round count to expect from those springs. I'd also seriously consider changing the extractor and locking insert at this point if the gun is going to serve any purpose beyond range games.