Most likely Assman & Sohn, Ludenscheid... I have similar examples if you want to see.
I'd rather be A "RaD Man than a Mad Man "
Relic-Condition WWI M16 German Stahlhelm...Around $50-$75 these days...
Ben Evans knows his buckles better than anyone else I know...
If the A and 38 are in the inside of the spade I would also say Assmann, the buckle will come off the belt if you wish, Idoubt the prongs are stuck on
They are any idea what it might be worth?