Found out some more on the Yello Bole line I was discussing in an earlier post. After some more digging, I found out that the Imperial line was Yello Bole's mid range line. In the mid 1940's they sold for $1.50. The Standard line was the low end, selling for $1.00, and the Premier was the high end selling for $2.50. The Imperial had a smaller sized "o" logo than the Standard. The "propeller" was the logo of the Premier line.