Interesting ex-HJ buckle modified for the German Police. Note the base, which is an aluminum HJ buckle produced by M4/44, aka Paul Kramer, on which the "Gott mit Uns" police shield was applied by piercing the buckle and securing it with the shield's four clips.
This practice was used several times during the Third Reich to recover or satisfy the increased demand for buckles for the army. For example, there are known HJ buckles modified from Deutsche Jugend DJ buckles.