[Charles Bavarois]

Hello Rbakerj,

"GFM" certainly does not stand for "Generalfeldmarschal" in this context.

I think, it could be "Gefolgschaftsmitglied" what is a typical Third-Reich terminus for members of non-military or non-NSDAP organisations. A worker at Junkers or Krupp would be a Gefolgschaftsmitglied of this manufacturer.

"Gruppe Feldwerft Gerät" is not that clear. An educated guess:
A Feldwerft is a military maintainance installation. In German Wehrmacht larger units sometimes were split into subunits for technical or administrative reasons, which were called a "Gruppe" (group). So "Gruppe Feldwerft Gerät" could be a subdivision of a Luftpark, a Schleuse or anything like this, responsible for Feldwerft-Gerät (equipment for Feldwerften).

HTH

Carl