did you ever fix the npap? Being an owner of two im curious.
I feel I had trouble with this too but I just fiddled with the trigger and cranked down on the safety and it went in. I also had the problem on both of mine where the sear was hanging up on the full auto safety during reset, causing a very loud click and felt slap during reset. I just filed a tiny amount off the snagging surface point of the century trigger rather than the yugo made safety lever. Just was a small clearance issue.
The trick for me was to grab the safety lever from the inside with needle nose pliers. that allowed me to install it easier againt the shepards hooks retention force. Made it from very frustrating to easy in seconds.
