The MP41 was created by Hugo Schmeisser, member of the devlopment team of the MP40.
This weapon was an hybrid between the MP28 (wood butt part) and the MP40 (corps part).
It was produced 26 700 MP41 between 1941 and 1942, the production was stopped because Heinrich Hellmer, the creator of the MP40,sue Mr. Schmeisser because of the telescopic breech, which is an ERMA* patent.
This gun wasn't endowed in the Wehrmacht, it was used by the Waffen SS, the Military police, and the Feldgendarmerie (Feldjäger posted in France).
5800 gun was give out to the Roumanian army, there is also probable delivery to the Croatia, Bulgaria, and Hungary.
*ERMA is the factory that produced the MP40
MP40 Product :
Folded and
Unfolded