Hello, I could now check it and, yes, the bayonet frog is (like the accompanying leather belt!) stamped DRP in connection with the abbrevation of the location of the certain DRP district.
As said, this has nothing to do with the metal backed frog with "only" the D.R.P. stamping which means "Deutsches Reich(s) Patent".
Regards,

wotan, gd.c-b#105

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