I have a Parker 45 Flighter with a black tail that has deep bite marks on it. They are too deep to polish out. Already tried that. I wondered about buying a cheap Flighter, hopefully with perfect black tail, but first please can anyone let me know how easy is it to unscrew these black tail end pieces? Are they all the same size and fitting method whether they are English or USA made? Are they glued in as well as being screwed in? If there are differences that I need to know before I start, how can I tell them apart? Thanks.