[Roger]

I have a 1955 publcation by "The Motor Cycle" entitled "Motor Cycle Engines" 2nd Series. There is a short preamble that say:

Famous British Designs Analysed: Details of modern power units, with unique explanatory-type drawings.

It has the usual stuff like Triumph BSA twins as well as a number of popular single cylinder engines, the RE Bullet 500 being one.

It is an interesting read and I will endeavour to scan the pages covering the RE Bullet  and post them ASAP.

Roger