1) Guy joined forum just to bash TPM.
2) Has little to no experience with MP5s.
3) Had a problem or two and blew it up bigger than it needed to be.
Perhaps now is the time to step back from they keyboard and wait till you get your gun back and shoot it. it seems you had unrealistic expectations about weld and fit etc. Despite the fun of the gun, rolling, aligning parts in jig before welding it is a ridiculously antiquated and expensive way to make a gun. CNC/FTW.