Thanks to Jonesy (mi hermano especiero) who not only brought much needed supplies to the plague-ridden, but also convinced me that I could in fact manage a 28mm ATZ game on my modest 3.5ft by 2.5ft coffee table, especially if we increased the size to 4ft by 3ft by laying a piece of MDF on top. That way the figures and terrain would be good for solitaire games as well as being taken to the club.
The next choice is (a) card model buildings over foamcore, like I did for the GASLIGHT game or (b) Matakishi style cork buildings. I've had a play with the latter scaled down to 15mm, so the next thing is to try a full size 28mm version.
As a third option, last night I started playing with some bits of foamcore and some printable brick paper and knocked up a simple frontage for some Victorian slum terraces. This will need quite a bit more work on the windows and doors than a straight up cardmodel pasted over a box, but should look a little less flat.
This is a hasty mockup, with the same pattern being used for both front and back. Inspired by Matakishi, I'm working on a 150mm x 150mm square footprint for building modules, but not including pavement in that space. So this building is 150mm wide and would be 100mm deep, with a 50mm yard out t'back (which is mocked up on the right with some scrap foamcore). There's a lot more tidying up and dressing that needs to be done, with lintels for the window and door frames, but I'm happy with it so far.
Once this is done I'm going to repeat the design but in cork, and try with and without the brick paper.