Heh, I've had a passion for vintage cars even longer than I have for audio, and that's going some! I read most of the mags, including the two (vintage)majors from Britain - Thoroughbred & Classic Cars and Classic & Sports Car.
Unlike the earlier cars I had to cheat, just a bit, on the Jensen. I knew it was a Jensen CV8 by sight, but I felt sure more than 68 had been made. On to the internet where I found that there were Mk I, II and III versions (didn't know that!) and that Mk I was a run of.........68 cars. QED.
You live in Bristol, yet you didn't find or photograph any of the lovely examples from Bristol Cars in Filton? A diversification of the Bristol Aeroplane Company, they've made interesting cars since the late '40s. I think they're still in business, more or less.
/Ken