Aye Steve,
I was in a flat opposite the chipper in Stanley Terrace when I was 'over' 1976-77 and the karts were absolutely magic.

The Rotax motors were "quick" and the Villiers singles (147cc) taken from the Bert Greeves, 'Invacars' weren't to be sneezed at round the Peel circuit.
Thank you for posting the link.
My regards, Bill