Here is my progress now guys. Just need to fill in some gaps and smooth it all out. Then PAINT.
The rear of the suppressor is made of Urethane (yellowish part), there are two large spacers in there that grip right to the existing barrel. Filled with foam, its super quiet, and seems like it somehow shoots harder.
It will be fixed on there like that forever pretty much, becuase im going to seal it with epoxy putty or something like it. Then i will sculpt the barrel and suppressor together so they look like its welded neatly. Should look nice with a few fresh flat black coats.