guy dances the Charleston on the train

I'm looking to find the name of a movie (or I guess it could even be a TV show) where a guy dances the Charleston on the train. I believe the train is on a property owned by an eccentric old man. Also a man and a woman swim to an island or at least a small patch of land in the middle of a river to be alone together. I believe it was a British show judging by the accents of the characters. I saw bits of it in 1995 so it is at least the old.
I would appreciate it if you could suggest what this movie might be called so I can try to find it and watch it as I can only remember seeing part of it at the time.

I found the answer with Copilot:
"Love on a Branch Line” (1994), a British television adaptation of the 1959 novel by John Hadfield.
Jasper meets the eccentric Lord Flamborough, who resides on a steam train on the private railway—the defunct branch line.