Out for a Sunday morning run on the 400 today, and bumped into a guy in Rye with a beautiful air cooled RD he had owned for 34 years, absolute peach, run back with him as far as Horsmondon, nostalgic blue haze wafting out the pipe, and credit to the guy, wasn't shy about chucking it into a corner. Been on the lookout for a decent RD for a while, think that will accelerate my search now.
A mates older brother had one, in red and white, back in the school days ! Such a basic design, hardly any design curves, and yet it still works visually somehow. Good luck in your search.