Thanks for all the replies so far folks; very interesting. Lots of votes for the Bombers, which I'd suspected might be the case. Superficially (such is my knowledge of fork internals), they seem to be the earliest design that has 'survived' (more or less) into the modern era.
Opening a further can of worms, what was the shortest travel on the early Bombers - 63mm? What adjustments did they have?
Pondering the age old question of period correctness vs. useful parts...