Planemike
My post re-Neil Williams inverted at Biggin states: "at a 1960’s BoB display" (my emphasis) so it was taken any time onwards from 1960 when I acquired my first cine camera which I used regularly until the early 1970's.
I can’t be precise about the date as my cine camera had no facility to date and time-stamp when a particular clip was taken, as with modern camcorders.
ISTR that Neil's Zlin was sponsored, but by whom I can't recall, and it was painted as part of this sponsorship deal. The markings on the surface of the wings is similar to other photos I've seen of Neil's Zlin in various publications.
FWIW the film was definitley shot at a September Biggin BoB display, not at an Air Fair, which I never once attended.