Andrew, I'd like a copy when you get chance, I've two copies, a hand draw BR one (off the web) and a more official LNER one (will scan this evening) with measurments and such like, though steam based it does give a good idea of the site and only a few tracks changed over the years, namely the additional one outside the huts close to the station throat and of course the removal of the Turntable, of which I cannot find a definative date and I'm sure there would have been a short crossover period when steam officialy left and diesels, specifically Deltics were there.