I have one 100% WLA made rear receiver section, and a WLA "80%" receiver, IE the 2 shells that need to be milled down to the proper size.
i found a picture of the detailed dimensions of the mg42. but have since lost track of it.
also, the one major difference on the SA vs FA receivers is the blocking bar that stops the un modified FA bolt from entering the receiver?
any links to prints would be greatly appreciated