When I visited, the layout was fully functional, but scenery was incomplete. The layout is about to be relocated so scene-building is currently on hold.
Since John is a bit of a 'rivet counter' I was not surprised to see the high standard of detailing on the locomotives and rolling stock. One of my photographs (the cab of a 'Rebuilt Scot') shows the detailing available on proprietary models these days - a bit of an improvement on the Rovex 'Princess' I was brought up with! John has added quite a bit of detailing of his own so the overall impression, with scale-length trains and correct formations for the period, is very convincing. There are a few, rather poor, pictures of mine linked below which I'm afraid don't do justice to the layout.
Here's a short video clip (in low resolution):-