Unit marking on RC Simson blank chamber P. 08: "M.W./L.u.V.J.3."

[318is_Parabellum]

Hello,
2nd post on this forum.

I recently acquired a rather interesting P. 08, and I thought that posting about it here would help shed some light on it's past...

Simson blank chamber serial # 5827
Simson and Co. Suhl marked toggle, all matching with Simson E/6 proofs on all small parts (including axle pin) except:
-the ground, renumbered/force matched sideplate,
-9mm 4 inch crown/N marked (replacement) barrel (original E/6-proofed front sight present on replacement barrel)
-sear bar replaced with plum bar w/ obliterated mark

Partial 'circle X' mark on front of frame below serial number (Russian capture mark, correct?)

2 E/6 proofs on stock lug bottom
E/6, E/6, E/6 and Weimar Eagle (firing?) proof on R side of frame/'barrel extension
E. German extruded blued steel marked "2/1001' with ground and forced match Al bottom

Sarco import-marked just above R grip (poor fitting wood replacement grips, no E/6 proofs on grip screws)

UNIT MARKED on front grip strap:

M.W./L.u.V.J.3.

I suspect this is a Weimar-era Reichswehr unit marking, the "M.W." means 'minen werfer'/trench mortar if I am correct?

Help with interpreting this unit mark is much appreciated!!

Sorry for the wall of text, I wanted to be precise in my description!

I thank the experts present here for their opinions and observations regarding my pistol!