The build begins. I've cut 'bolster' pieces of 2x1 for screwing the curved sections to, together with cutting a fair few (but not yet enough) stanchion pieces. The first board is now at the end of its initial build stage. There's crossbeams and diagonal strengtheners to go in to stop the board being able to twist (which it is doing ever so slightly), but it's pretty flat considering. There's also a bit of tidy up work on one corner where the outer curve is a couple millimetres too long. Otherwise, looking good

Underside showing stanchions and bolsters:

Topside:

Topside with template: