Is it a Weimar era police marking? S. Me. XI. ?,4??
I can't make out some things without different lighting angles.
https://oldmilitarymarkings.com/police_unit_marks.html
If Weimar era Prussian Police, the table indicates:
S.Me. Merseburg district
Marc
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Igitur si vis pacem, para bellum -
- Therefore if you want peace, prepare for war.