3rd Reich Kriegsmarine WW2 or pre war aluminum buckle

3rd Reich Kriegsmarine WW2 or pre war aluminum buckle. The buckle is  Rudolf Souval and Son made, however it’s not properly marked and just an upper part of the R.S &S logo is visible. The buckle is well worn, and practically all of it’s gold finish is gone. The fastening roller has a damage due of long time wearing. It’s a Estonian attic find in the area of Sinimae village (Kinderheimhohe) where was a strongpoint and some of the German navy coastal troops fought there. The upper part of the buckle has a very minor crack, may be a fragmentation damage. In general  it's a good condition buckle.