I think I've identified this car as the "Cripps Special." I've found the names (initials) J.A.F and W.L Cripps associated with it at the 1951 Gosport AC Speed Trials, although I couldn't find any association with Brunton.
After that, I've run into a brick wall. Imagine googling "cripps (or crips) special"....if that's not clear to ya, the crips are a buncha gansta hoods...the ones with the blue hankies. It kinda clutters up the results. I think someone else had a similar problem with another search string...but my memory issues are acting up and making things fuzzy and causing me to write long, stream-of-consciousness, run-on sentences. Sorry.
RtR