1935 Bugatti type 57 Stelvio Cabriolet by Gangloff. Body designed by Jean Bugatti but made by Gangloff, quite a few of these bodies were made, all very alike and difficult to tell which this one is, could be chassis 57197 or 57314
The one pictured bellow is 57103, the very first Stelvio presented at the 1933 Paris Salon.
Notice it even has the same rectangular cover on the front mudguard