Not a buckle expert by any means but I have seen unmarked ones and to me the "notch" looks like wear to me.
An alloy buckle rubbing on a steel catch perhaps?
" When you're chewing on life's gristle, don't grumble, give a whistle "
Could be something done the soldier for comfort or placement of equipment?
Searching for anything relating to, Anton Boos, 934 Stamm. Kp. Pz. Erz. Abt. 7, 3 Kompanie, Panzer-Regiment 2, 16th Panzer-Division (My father)
I've got a few well worn alloy buckles that have similar wear patterns. Some both sides, some just one side. I'd put it down to wear from a steel belt hook...
Yup, i'd say wear!...
It's a wasted trip baby. Nobody said nothing about locking horns with no Tigers.
I'm Spartacus, not really i'm Paul!...