'One's outstanding impression is of the exceptional flexibility and smoothness of the engine – it seems almost incredible that so much docile punch should be the product of no more than one cylinder and an 8.5:1 compression ratio,' Motor Cycling enthused about its test Viper, summarising characteristics that will be familiar to anyone who has ever ridden one of Hall Green's delightful high-camshaft singles.

This beautiful example was despatched new to West End Motors Ltd of Upper Tooting Road, London SW17 and first registered on 11th December 1962. Wets End Motors retained the Viper until June 1963, presumably as a demonstrator. The machine came into the current vendor's possession in 1982 and has covered only a minimal mileage since undergoing a complete 'last nut and bolt' restoration in 1998. We are advised that a new magneto was fitted in 2009 and that the machine is in 'as new' condition. Finished in the marque's traditional black livery, this fully restored Viper is offered with sundry restoration invoices, expired MoT certificate (May 1999) and its old-style buff logbook, which may enable the original registration number to be reissued.