Update: the final one. (hopefully )
Well thanks for your help OG671 because I ordered that part (and 13 days later... ) it arrived in the mail!! Well needless to say I installed it into the gun, aired it up, and bobs your uncle! Who's your aunt you might say? I am. That's right kids, I already had it!
Nah but on a more serious not thank-you very much for your time and help!