psg1 clone

So, hi. First post here, I made an account just to ask this question. Sorry, I don't know how many times people have asked questions like this, so I apologize if this is an annoying subject, but I have to ask. Let me also preface this by saying, I know nothing about guns or gunsmithing. This is...

PTR-91 PSG-1 Clone Affordable alternative to PSG-1. Inspired by a post of robfurrow. I'm waiting on a barrel extension like his. Also wanting to put on the PSG-1 forearm but don't understand exactly what that requires, rails? a trunnion adjustment? removal of the triple frame front sight...