I would use early Tamiya 1/35 holsters, 8th Army especially.
Tamiya 1/35 8 x British 8th Army # 35032 
They are woefully underscale, entirely too small even for .380 revolvers, so quite useful in 28mm &, being plastic, clearly carveable...
Tamiya's German offerings of that era are worthless, useless, shapeless lumps, following no known prototype. Their American gear might just do..
Any tank modeler or dioramist oughta, have plenty in their bits box.
EARLY Tamiya mind you, their recent stuff scales properly.
Valerik
"There are two refuges from the miseries of life: music and cats."
~ Albert Schweitzer