I got a nice surprise in the 1928 Budapest phone directory. A man with the same surname living with my great grandparents. My guess is he's my grandmother's brother (she was born in 1906 so an older brother could easily be the right age), but I don't actually know.
The listing reads:
Krieger (Kriger).
— Béla, masántisztv., VII, nefelejts-u. 45.
— József, keresk., VII, nefelejts-u. 45.
So I know that they lived at 45 Nefelejts Street in District 7. Jozsef, my great grandfather, is a merchant and Bela is a Second Commander in the Army (according to a kind soul who translated for me).
I can tell you that the KRIEGERs were originally (and fairly recently) from Kosice, now in Slovakia, and the family is Jewish.
Is there a way to find out more about Bela? Who is he? My great uncle? Another relative? Are there military records that might have him listed?
Thanks!