It IS Josef Kulzer's Fiat Spezial!
VEEEEEEERY GOOD!!
And it still exists!
Here are some details:
built in 1940, 4 Zyl., 1089 ccm, 50 PS
Here´s a big picture showing it in front of the Petermax Müller VW at the Schanz race at Ingolstadt.
He won this race that took place at the 15th of August 1949.