Hi Ian,
That looks quite marvellous - I am doing banbury in OO - no further than the baseboards at the moment! lucky enough to have 7.5m x 4.5m room but the station is still hard to fit in.
I have been working on a google sketchup of the station building and so I know just how complex it is and yours looks a fantastic representation. I am modelling it circa 1962 but apart from the lights and signs and a little track plan difference it is much the same modelling problem and I know I wont get it as good as you have.
Good luck and would love to see many more photos - and track plan if you have the time.
Cheers
Tim