I must apologize any confusion wich my post # 357558 might have caused.
I cross-ched two additional German filess for possible supplements:

1 - Eugen von Halász de Darbas published in 1996 a well researched book 'Deutsche Kampfmesser' (in English: German Fighting Knives)
Two options of the "DEUTSCHER BRUMMER" knives are being featured:

[Linked Image from i.imgur.com]

1.1 Anton Wingen Jr. cutler's early pattern knife illustrated with "left hand side" photo: starting letters "D..." and "B..." with large 'loop' style underlining, "D.R.G.M." mark (see post # #357544) , black color ferrule and black cap at the bottom end .
The sheath is said to be out of metal with both press button safety for the guard and the belt loop.
The description is mentioning "J.H. Becker Solingen" as optional cutler.
1.2 A `'private / civilian' option, illustrated from the reverse side, reverse blade side without etching (front / left hand blade side possible marking unknown!)
The sheath out of brown lether with silver color tip, press button safety for the guard, belt buckle safety for the knife handle

2 - Christian Méry 'Deutsche Kampfmesser 1914-1918' (German edition published in 2013 by Wieland Verlag), original edition 'German Combat Knives 1914-1945" published in France by 'Histoire & Collections
Two illustrations are showing up the front (left hand) side of two Anton Wingen knives.
One knife's blade has an identical mark to Eugen von Halasz's # 1,1 mark,
and the the sheath is of "German Nicker knife / Bavarian Dress Knife Style" i.e. a leather sheath without belt loop, and metal fittings both at top and bottom end.
The other knife's photo is of quite poor quality, you cannot identify the left hand side's blade marking, it is said to be "Deutscher Brummer".
The leather belt sheath is quite unique with two belt loops, blade cover of 'German Nicker style', with a pommel as decoration.

chevalier2022