A very good friend of mine lived at Four Marks with his garden facing the railway line close to the station. He built a model of the Medstead and Four Marks station.
He was a very skilled man, amongst many other things, a draughtsman and he measured up and drew drawings of the buildings. He built most of the buildings etc. from those drawings.
If you can, please look at the December 2012 Model Rail Magazine that includes a 7-page article.
I believe that his wife might still have his scale drawings, if of interest, I would ask if he could copy for you.
I look forward to following your layout.