I have a first generation P3AT (actually, it was one of the first 300 made). I have noticed while watching some videos and looking at some pictures of the new ones, that there seem to be several modifications made since mine was made. Can someone tell me exactly how many things have changed and what they are? And if I can send it back to Kel-Tec to have it "updated" and how much that would cost? Any help would be greatly appreciated!