As Matt said. The logo with the lens shapes is an old Mamiya-Sekor logo, and the pins should fit several Mamiya medium format cameras, including the C series TLRs and the M645, and possibly others.
I've occasionally seen other flash brackets with the cold shoe at a 45 degree angle as well. Never been entirely sure what they were supposed to be used with. Possibly they are intended to get a large flash reflector out of the way of looking down into a waist level viewfinder.