As I have looked at posts, some old and some new, I have run into a lot of comments about incompatibility of old and new parts. One thing I have not seen is links to any type of cutaway view or cutaway diagram that shows the relationship of the trigger/hammer group components and how they change position during a shot sequence. In other words, showing how each part interacts with the others to make the shot go off but also make the safety functions work. I have seen such graphic descriptions for a 1911 on the internet and wondered if anybody had ever seen one for the USP. In my opinion a clear understanding of how it all works not only makes it easier to understand how the parts become incompatible but also to address assembly and disassembly. Have you seen such a presentation or graphic model?