When a gap allows, would the mods permit, in the interests of accuracy, a reference back to post #4229 , concerning the designer of the Mann & Grimmer M. 1? That 'Mann' was not the Mann and Edgerton Mann, who was a Gerald, but one of the two people who designed and sold early A-frame twin pusher rubber-powered model aircraft "guaranteed to fly at least a quarter of a mile" in Surbiton just before WW1. The south-west suburbs of London seem to have been quite a centre of activity for both model and full-sized aviation around that time; as well as Mann and Grimmer, Sopwith was based at nearby Kingston as was Clarkes, whose main product was aircraft propellers, as well as Britain's first ready-to-fly model aircraft.
The subject and a lot more is covered in detail in A Century of British Free Flight, published by the British Model Flying Association. Is a link allowed?
https://shop.bmfa.org/product/a-cent...ee-flight-book