The rubber butt pad has not been touched its as it came with the gun, the camera mounts needed no work they come drilled and threaded. All that is needed is the 4mm aluminium plate that is up against the stock and the rubber butt. I used the rubber butt as a template drew around it onto the aluminium plate. Then a hacksaw and file and drilled the holes. Its easy but time consuming. The high polished finish i got is obtained by using ever lighter grades of file and emery cloth and then metal polishing auto paste. And also you will have to file the picatinny rail. Its a fair bit of work, i like a bullpup for the balance but the neck position plays with my neck and i could find no adjustable buttpad that i liked so i was forced to come up with this or ditch the rifle which i did not want to do. Aluminium is fairly soft so use a ruff file and saw and a vice. I do have lathe, cnc machine, bench drill etc and still did it by hand, even with modern tools when making a one off sometimes its easier to get stuck in and do it by hand. Good luck