ive been working on a pps-43 for years and been hung up babysitting my granddaughter. ive got a receiver that need the denile bar in it but i need it straight and true. plan on using key steel and taping it to put a scope mount on it a weaver or pictanny, excuse the piss poor spelling. after i get the trunnion in it can anyone put the bar in it and just drill the rail holes, ill tap it? how much?