jimbofin

You can still pick up the Prototype Models Kits, for instance from Antics https://anticsonline.uk/Category/Bilt-Eezi--Prototype-Card-Kits_N1940

I have a small stash from my own ideas for building an Em version of TAoC. However the printing, by modern standards, leaves a lot to be desired. I've even tried improving them in Photoshop with no success.

So my suggestions. First of all you could buy the kits and use them as a template, perhaps using some Scalescenes textures to replace the originals.
But on TAoC the buildings are very close to the viewer, so it might be worth using laser cut kits. York Model Rail do a suitable groundframe, though I would be tempted to put a signal cabin on the platform. Arch  Laser do a Fairford Goods shed.

Years ago, I got Lcut to produce a lasercut version of the platform building. Somewhere, in amongst packing cases, I still have the preproduction version.
And Intentio do a GWR weighbridge.

Hope this helps

First of all glad to see TAoC has gone to a good home. 

If you look at the prototype plan of South Leigh in the same issue TAoC appeared in I suspect it provides a clue as to what partly inpsired the track plan.