Red- I really appreciate your response. Actually, I think a large(r) fire extinguisher was part of the basic equipment for police bikes back then. So, the installation location was accounted for in the design. This extinguisher came later...like the early 50's- early 60's and is a thin chrome affair, much smaller than the one I've seen on early police bikes. 91623-52 is the part number and it is like the brass "Presto" brand home fire extinguishers of the period only chrome instead of brass. I REALLY appreciate your interest and comments!!!!