A little update. I've tweaked the plan for the fiddleyard to get it to work with the 15 feet 4 inches room it could be set up in, such that I can work on 8 foot vignettes. Previously it had been measuring 15 feet 7 inches in length and that of course wasn't going to fit. The tweaks on the throats have brought it to 15 feet 2.5 inches, allowing a little bit of leeway:

I've printed out the throat boards, sellotaped them together and cut them out so I have full size templates. Those have been outlined onto existing plywood boards I have ready for cutting whenever I can find a suitable place/time to do so.

I've also ordered the first few of the turnouts so that I can check them against the templates before any cutting takes place, and also to check that trains can run through them smoothly. I've read that with so many facing points in a line that might cause issues, so I want to be reasonably sure they are suitable.