Good job Gary! But looking at their email, I suggest you discuss with them on how much u wanna charge (if you want to charge). If its free, they better give u a good reason, and whats your mileage.
More importantly, bear in mind some areas, installations, equipment; buildings, and in this case; the company that owns the train may have some legislation, especially for commercial reasons. Dont want to get to the wrong side of the law.
let me dig out some note/documents for u tonight. May not bullet-proof u, but its up to u to decide after u see em. i will pm u my hp.