I'm no help, as my PT145 MilPro is 2nd gen and I'll admit I've never broken it down that far. I'm sure one of our Millenium experts will be along with your answers.

 

No help at all am I. I don't own a 145, but as soon as your post got to "finally broke it free", that sends up all kinds of Red Flags. I am sure someone is going to come along , identify the parts and explain reinstall . Just got a be patient and do not "break anything else free". Good luck.

 

I should clarify it was a mixture of what I'm assuming is years of carry dirt, lint and solidified lubricant of some sort around the firing pin. I tapped the back of the slide on my mat to dump the pin out and these two pieces appeared. I would have been fine if I removed this myself.