No it's not a factory document but it has drawn on many sources of useful information and exploded diagrams from down the ages and is a very comprehensive and worthwhile read. Other similar and somewhat better publications are the Paul Richardson book "Vincent Motorcycles" and "Know Thy Beast" by Eddie Stevens.
Peter B
General Editor Bernal Osborne of Motor Cycling with Scooter WeeklyVery similar to the Bruce Main-Smith book I suspect. The title sheet states mine was written by BMS of Temple Press and first published in 1960. My copy was purchased by my father in 1980 from BMS's shop in Leatherhead for £1.75.
Does it mention who wrote it and when in your's?
Steven
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