WOW! Just came across the thread. I used to live in Flackwell Heath as a youngster and my fathers friend who worked on the railway (sadly passed away now) actually had a short spell at Loudwater Signal Box and apparently, at the tender age of 5, I was taken inside there. Fennel Woods were a big part of my cycling days as a nipper and I have vague recollections of the railway being there and the gates. Not a lot there now unfortunately, but you can still walk part of the old track.
Loving the layout. Steve