What a day! I decided that since the casting is messy, and I have to wear a filtered breathing mask to avoid breathing in the hydrostone dust, and goggles to avoid damaging my eyes from the hydrostone dust, and all the mixing, and pouring, and waiting, and scraping, and waiting, and demoulding, and starting over... I'll do it maybe once a week. So, I spent the whole day and yesterday evening casting pieces, so that in a three or four days time, I can make a corridor section, and a room section. I definitely enjoy the assembling and painting part of this more than the manufacturing part, but seeing pieces finished makes it worth it.
Anyway, here's the mammoth set of pieces I cast! Now I just have to wait for them to dry. After making the corridor and room, I should have a couple pieces left over too, so less casting required next time :)