"Werksverteidigung"

[der panzerknacker]

hello; my father worked in Eisenach/BMW as a jet turbine engineer and flew sorties on Fw 190's of the 'Werksverteidigungsstaffel' (factory defense squadron). He passed away in 1988 and no material - written or graphic - survived the war so I wonder if anybody happens to have more info about those factory protection units. I'm trying to model one of those aircraft and also complete my father's life record, hopefully.
greetings & thank you