MA401 MÄRKLIN 346/2 (4008).6 (1954 ONLY) RED ‘DSG’ DINING CAR
Identifying features including die-cast bogie sides, stump axles and flat destination boards date this coach to 1954, Koll's Preiskatalog version 6.
It has had a hard life and there is significant surface rust in paces. Still, with a bit of TLC, it would make a lovely runner for your layout.