[Dynamo]

you can't change engraved markings into relief markings. they have to be done either during casting or they need to be pressed onto the surface. basically pressed into a dye that has the marking engraved. since that would take a multy-ton press, it can not be done on an already formed receiver. the marking are usually put on before the receiver is folded into it's final shape, like when the sheet of steel is being stamp cut, it adds the markings then.