The image comes from a very optimistic article in the April 1982 issue of Classic Bike, Ian Thompson's company was making an all new cafe racer, using a replica Norton Featherbed frame and running gear, using a derivative of the Weslake DOHC speedway engine converted to dry sump form. Power was described as "adequate" and any minute now anyone with about £5000 would be able to take one home. Unfortunately, Weslake went into receivership just after an order for twenty five engines had been made. End of venture.
I hate to say it but the Weslake doesn't have the visual presence of the Norton engine at all.
There is a bit of info online on a similar cafe racer project with a 5 valve Weslake engine installed, and an article on the Brooklands company adventures in the Feb 2020 issue of Classic MotorCycle.