Nice to see the padlock and chain rattling on the paintwork:grinning:
The Arm of Service serial '51' with the 'Corps' bar above is shown in the June 1941 listings as "Corps Troops Ammunition Company" (RASC) ...Presumably CRASC as well.
This must be one of those early 3SWs...The speedo loks to be black and the bars and controls are plated.
Unlike the M20 handlebar mounts which are cast as one with the top yoke, the Triumph mounts can swivel and this rider has his completely upright (risers?) actually in front of the steering damper. I guess another strange approach to riding position from a Canadian, who were maybe more used to Harley's/Indian's? Ron