Nicht zer gut, Herr Parkeristo-- if you thread the receiver stud into the mating female threads in the rear receiver face, then try to bend that stud to fit the replacement buttstock, you had better hope you got it right on the first shot out of the box-- I would ash-can the after market buttstock idea and look for a parted out field grade M12 buttstock post 1935 design most likely.
M12's, like the "using grade Paakars" are treasured artifacts of a by-gone era in American shotgun manufacturing, why be in a rush about doing a "Comshawed" stock replacement job on a buttstock? RWTF...
