After victory in the 1920 Junior TT, AJS's new overhead-valve 350 racer scored a memorable double the following year, Tom Sheard winning the Junior race, and Howard Davies the Senior - the first time such a feat had been achieved on a 350. The production version made its debut in November 1922, delighting clubmen everywhere with its 'racer on the road' performance. A right-first-time design destined to achieve countless successes in the hands of privateers, the overhead-valve 350 AJS - latterly known as the 'Big Port' - changed only in detail before being superseded by a much-revised M6 model for 1929. The latter's engine incorporated a number of improvements including enclosed rocker gear and dry-sump lubrication, while the frame was redesigned to accommodate a saddle tank, and Webb forks replaced the earlier Druids. This matching-numbers twin-port M6 was purchased at Bonhams' sale of the Professor Fritz Ehn Collection at the RAF Musuem, Hendon in June 2008 (Lot 218) and since then has been completely renovated. Works carried out include replacing the main bearings, gearbox bearings and wheel bearings; re-spoking the original wheels; overhauling the carburettor and speedometer; replacing the oil feed pipes and exhaust locking nuts; and fitting two new silencers. In use this summer, the machine is offered with restoration invoices and a V5C registration document.