The chap in the photo is J Wimbourne, who is presumably the first owner of the car. The photo was taken in July, 1949. It was later supposedly later owned by Basil Jones in Rugby in the 1960s (so doesn't quite fit with the account given by the current owner, but he probably knows better).
Interestingly the car seems to have changed colour very early in its life, from what looks like silver in 1949 to white (which, sadly, has only just been stripped off) according to an early colour photo I have... or maybe it was always white and the Eastbourne photo is just an optical illusion?
I'm in touch with a former Leacroft employee so may well have some more information at some point