Casa Zepelin 1929 (Bucharest, Romania)

We have two of these unused cards. They have no printed caption, but we know they are somehow associated with a restaurant in Bucharest because one of the cars has a rubber-stamped chop with the name and other information (Grade: 1, $2). The other card says nothing (Grade: 1, $1). And we only learned this much through extensive Googling.