Visited the big green shed today and made myself a notched flat edge. A couple more quarter turns of the truss rod and I think I’ve got the neck as straight as I’m going to get it. Tried to make myself a 12” radius sanding block (what a clown!), soon gave up and ordered one online. I wasn’t looking forward to this stage of the build, but the more involved I become the more I’m getting enthusiastic about getting the neck set up as well as I can. I’m sure the effort put in here will be well worth it in the end.