The only I. Just that might be around in the early 1950s is Ignaz Just, mentioned in 1938 as a gunsmith at Steyr. If he went (back) to Ferlach after WWII he might have been one of many home workers employed by Franz Sodia (and others).

Maybe our distinguished member from Bonn could see about the Bock's ledgers. Or, alternatively, if anyone can penetrate the Ferlach Beschussamt, the ledger number will tell the story as the pertinent books are still there (I had some luck with them in the past, but they remain in silence in recent years).

Cheers,
Jani