Long time no time to go down. However, I have picked up some other snippets which may encourage a positive interpretation of the SOE connection. Someone who grew up in Dover when I was there who I met by chance recently had become a teacher of French himself - there had been an organisation of such people, and the president of it had been involved in training people for SOE during the war. And my sister told me that at Dover Grammar School when she was there, there were two teachers, a married couple, also teaching French, who went about with the Legion D'Honneur flashes in their tweed buttonholes, and were not as close mouthed as some have been about war time work. (Four years after her, my other sister knew nothing about them.)
So, any war work connection becomes more likely than that it was imagination.
Someone suggested that railway signallers might have information about the train business, and I have contacted a group of enthusiasts - unfortunately that was a dead end.
