If the straps are Bavarian, the Luftschiffer emblem would be just be the “L” without a battalion number as in Sandy’s example “Luftschiffer Betriebs-Abteilung” Plus Luftschiffer Batl 5 was a Prussian unit, (Graudenz, I.AK, raised in 1913). The backing would be gray as well, as in Steve’s...