The blueprints for the Money Bin which were assigned to Frank Lloyd Drake were actually designed by K.D. Rosa, in 4/5/1902. The Keno Rosa Company of Louisville, also was set to supply the mosaic tile design.
Don Rosa and his wife are also seen enjoying the sunset near the Superstition Mountains around the mid-50s, in "The Dutchman's Secret".
Due to the huge chronological difference between the two events, it is possible that "Keno Don Rosa" refers to two different characters, with the architect and tile designer being the grandfather of the Don who is seen in the Superstition Mountains, hence passing on his name.