I recently got hold of some Airgun Worlds from 1983.

Trapshot were advertising the "Venom Hunter" as per the John Darling stock configuration.

Also in these issues John mentions he has "just fitted an Optima Supermoonlighter" to his HW80. The pictures in the magazine show him only using a HW35 with open sights! There is a shot of him using a HW80 but it looks like a normal one - might actually be his FWB - will look closer a bit later.