I would agree with Steve. The Frame is what determines a vehicle. It's the part that the authorities would acquaint the vehicle to. Plus your frame is recorded and therefore much easier to determine the spec. Mine is from the next contract. By then they lost the steering damper and were fitted with the 7/8" handlebar and standardised Amal controls. Ron
PS My 741 is 1942 ex British Forces under the Lend Lease scheme.