Been scanning some of my old colour slides and came across the following from around September 1987. My decaying brain cells cannot fully remember the circumstances but Southern Region were running an all stations shuttle between East Putney and Wimbledon as a replacement service. I don't know but it could be that this was because the Thames bridge between East Putney and Putney Bridge was closed. Has this sort of service ever been repeated? Pictures of Southern train taking on passengers on East Putney SR platform.
I can't answer your question but I used East Putney a fair bit during the early nineties and I remember there were a number of oddities because it was a BR station through which only LU trains operated (normally).
One of the anomalies was, IIRC, that although it appeared to be an underground station, you could smoke on it when you could not smoke on real underground stations.
I never saw a BR train operating there and I could see the line quite clearly from the office window as I was working at the top of the red building in the background of the lower picture.