If it's an MG34 receiver we're discussing, I believe that the pin is machined offset out of the same metal block as the rest of the receiver. It doesn't remove.
A machine shop can turn down the pin from your receiver lump...then you set it into the counterbore in your new receiver and weld it. That's how TNW does (did) it. They used to sell them.
Bob at Philadelphia Ordnance (makes) made MG34 receivers and sold (separately) the pins at one time. He may have some, or be able to salvage yours. Their later receivers have the pin/cam assembly bolted on.
The newly made ones typically aren't "threaded" where the shroud pivots on....Phil.