The only thing I have seen is a Microsoft Train Simulator addon which
would certainly help in general terms.
It's not free though. See:
\\Products\ MS Train Simulator add-on packs\ Severn Valley Railway
A review here:
Wasn't able to find a copy on the shelves though..
If you are near Brum you could ask (or phone them) at the local
history section in the B'ham central library to see what they have as
pictorial resources? (Near top floor?) but Kiddiminster library might