Engineer Leo Kusmicki, working under Norton team manager Joe Craig, tweaked the dohc short-stroke version of the engine until it produced near-as-dammit 50bhp at around 7000rpm (and Leo even extracted 36bhp at 8000rpm from the 350cc version).

The result was a racing package of just 310lb, capable of 140mph, and which proved ideal for the riding style of one of Britain’s rising stars. Geoff Duke and the Manx Norton became world champions as a result.

Even today, a standard Manx is a formidable opponent on a track. Dave Catton fondly recalls ‘beating a 750 triple BSA through the bends at Chertsey track day.’ The bigger capacity bike would pass Dave on the straight – just – but ‘I passed him every time we got into the bends!’

When Dave first got the Manx it was a little tatty, and needed a good tidy up. Dave stripped and rebuilt the machine, but wisely chose to get an expert to tackle the engine work on the complex cambox. ‘I had the cambox rebushed which cost around £500,’ he explains. ‘I used the services of the Norton Owners’ Club cammy expert to strip and rebuild the cambox for me, while Andy Molnar machined the cambox and supplied the parts.’

The frame and tanks were repainted, and the Manx was good to go. Dave rides his Norton in parades and demonstrations – he’s also taken it racing in the past but takes things a little easier these days. The Manx has behaved perfectly apart from a split oil tank, and always impresses Dave with its ‘handling and overall performance. I don’t really think it could be improved – I just love it as it is.’