Ok, still looking for it.
The model used for races was a 20 CV, so it was derived from the Typ B, that was a 20/28 CV (Typ C was a 12/16CV).
Can't find the right event but I found F.A.B. racing at SPA, Liedekerke, La Fleche, Tours, Laval, Suede in Stockholm in 1912 and Namur in 1913.
Was it a 1912 event?