Today was productive – I got more done than anticipated. After lightly sanding the flash off the wall segments I did a trial assembly. The fit is quite loose, so assembly was no problem at all. Then I applied a strap clamp to judge the size and fit. It was fine. Diameter is now 565 mm, almost exactly what I had planned. Then I applied glue to the interfacing joints and clamped the assembly for several hours. While the glue was setting I realised that the first pass pieces could be trimmed to use as infill. I set my mitre saw to the correct angle and trimmed the tenons off. That left several extra pieces and the remaining short board. It was all just enough to do a second course of infill.
Now there’s just the 290 mm diameter centre which I will infill with the remaining second attempt board sections. They will be rectilinear, since radial pieces would get too small to machine safely.