Hi Phil,
Fantastic thread, enjoyed all your previous pics too.
You might try here for some 25 gen:
http://www.derbysulzers.com/
Failing that, you might want to PM a member here (if he's still here of course), 'Etched Pixels'. I do recall he was quite a guru on the ins and out of the class 25 locos. I do know they are a minefield for their minor/ subtle changes within fleet..
HTH, keep up with the pics please.
Cheers
Lee