Hello, HACK-WERKE STEYR, owned by Josef and Gustav Hack was a smaller Austrian knife maker. During III R they did produce mainly SA/NSKK daggers, HJ knives and walking out dress bayonets. Only few army/luft daggers.
A further makermark with the lieing fish and "Rostfrei" beneath is known.
It is the same like problem as with ZEITLER edged weapons: They DID produce a lot during the III R, mainly for the now "Ostmark" demand, but after 45 there had been a large amount of surplus parts and these were used (ZEITLER´s by Atwood; HACK´s by the firm itself) to assemble edged weapons long after the war. Imho it is always necessary to look if a certain dagger has a homogenous look, if all parts are well executed(!) and fitting nicely together(!!). If this is not the case it might be a past 45 compilation.
After 45 they did produce mainly hunting knives until they got liquidated in 1981.
Regards, daggers.

wotan, gd.c-b#105

"Never look for sqare eggs" as a late owner of an original FHH-dagger used to say.