Thanks for adding the details, what for Eagle/WaA is on the grips?, there is assembly or ser. number of 8695, most real from old piece where it was mounted by production.When there is a WaA883 it could be for Solingen area producer of 1940-2 period. Flashguard is too mixed there is 581 number, which is not on bayonet.
On S/155G are two sets of serials, one 8113 for fg and grips and other 159 for locking lug.b.r.Andy