sorry will be at the Tenterden Festival this weekend- always interested in railway songs though. There's a steam 'folk train' there, and last weekend the Marshlink had singers on promotional; trains, so it looks as if this is a good idea- captive audience etc!
If you like, I can send you the song 'old Country Train'which I wrote a while ago- it relates to the Hawkhurst Branch, but is easily made relevant to others- though the glossary of coppertops & converts & cromptons, come to think of it, is longer than the song! Let me know if you'd like a Southern element...