I have 2 CZ Custom SP-01 Shadows I've been shooting in USPSA for years. The first one is 9 years old and likely has 100k rounds through it. It also has a huge number of dry fire drills through it. Out of the box, it was possible to put the thumb safety on, even with the hammer down. It is now possible to do a DA pull right through the safety.
The other one is 7 years old. It probably has around 30k rounds through it and very little dry fire. The safety can not be put on when the hammer is down.
What is wearing out and how do I fix the first one, preferably so the safety can't be put on when the hammer is down?
