Gosh, yes, I'll try David.
The first Aylesbury (later known as MK1!) was smaller, portable and certain shortcuts were taken which he later realised meant it could not be operated in a prototypical manner. It was exhibited at Central Hall Westminster at least once. The goods yard was abbreviated, the whole thing shortened and the track used GEM fibre sleepers. Information came in which showed that some assumptions he made about how it had been in pre-Grouping days were wrong, and in the end he decided to sell it and start again, making all critical areas exactly correct scale including all the buildings. The new model used EM-Society plywood sleepers with shoe brads riveted in and soldered to TT flatbottom rail, which was the nearest thing to scale available at that time. Very few people simulated chairs in 4mm at that time, but he used blobs of Polyfilla cut to shape with a knife - no real detail, but gives the impression. The old GEM sleepers had arched their backs increasing the gauge and he noticed that trains ran better where that had happened, so Aylesbury MK2 was built to the non-standard 18.2mm gauge many years before that became the standard. In fact he was ashamed for many years that he had not stuck to the published track standards, so didn't tell anyone!
Aylesbury MK1 was sold to Pat Whitehouse, father of Michael Whitehouse of Tyseley. When I was last at Tyseley many years ago, Aylesbury MK1 was still there, on display. Perhaps it still is?
Aylesbury MK2 he determined would not warp or move, so the baseboard was blockboard on 2in x 1in pine supports, themselves resting on 2in x 2in solid drawn angle steels resting on the roof timbers of the loft. It was solid with a capital "S", as you will have discovered! Cork was used under the track and the sleepers glued down solid. Once the track had been laid it was gone over with a piece of 2in x 1in with the ends planed off like a punt and covered with fine emery cloth. This ensured the rail top was dead flat (never mind the profile of the rail head!). It worked, because after all those years the only problems we even had with track was the odd pint blade becoming dislodged, mainly whilst track cleaning, or H&M point motor switches sticking. It was utterly reliable.
I think the various articles starting in the 1950s in Model Railway News, Model Railways, Model Railway Journal and Model and Miniature Railways might give some more background.
Mike