I have what appear to be a 7.92 Kurtz and a 7.62x45 Czech in plain, unlacquered steel cases. The headstamp on the 7.92 Kurtz is “AK — St 4 45” and the 7.62x45 Czech is “bxn 54 (inverted)”. Were either or both of these rounds made with unlacquered plain steel cases? Or has someone stripped the lacquer off. There does not seem to to any trace of lacquer in the extractor groove, etc.
If they appear to be ball rounds in every other way, they were probably just stripped and polished.
Jon C–Yes, they are both plain Ball rounds. If they were stripped of lacquer it must have been done chemically as I can find no trace of lacquer even in the headstamps.