Is there any emblem in the dead center of the hubcap? can you show the whole hubcap please?
Im thinking STudebaker because they hqd several ARt Deco style caps in the 30's
A STudebaker woulda hd a big stylize "S" in the center (sorta like Supermans tee shirt)
Other than that, its gotta be some sort of art deco thing from an old brand(Packard, Franklin, Grahm -Page etc)