I’ve got a freakishly long truss-rod access slot, for which I need a freakishly long truss rod cover. I tried recessing a rectangular cover, it’s alright, but not quite a good enough fit. So instead I’ve gone for a spikey/curvy affair to fit around the first tuning peg. It kind of works.
I’ve made up a control cover plate, and I’ve been working on a router template to suit. In the long run, it would make sense to make up matching internal and external templates, and that’s probably what I’m going to do next time.