Hello derjager and Gaspare, thank you for looking. The facktory where this Werkschuz memer was on duty remains still unanswered.
@ Gaspare, as the arm patch and the badge on the peaked cap are clearly Werkschutz there is no doubt.

I already did contact special german buckle collectors without luck.

Regards,

wotan, gd.c-b#105

"Never look for sqare eggs" as a late owner of an original FHH-dagger used to say.