Thanks Dan, the soak and heat process was in my mind. Did you notice any advantages to the curved back other than looks?
Yes they are pretty, but I couldn't distinguish any tonal quality changes. The center of the jig is "proud" of the frame, when you tighten the bolts it bends the panel into place. Wetting the panel in hot water in the bathtub, then using a hot air gun whilst torturing the panel in the jig. Hope this helps, always fun to experiment!