Greetings,
Just for kicks I'm building a Beard roundneck resonator kit. Plans call for a tapered wedge under the fretboard extension rather than angling the upper bout. When I cut the fretboard taper using Sylvan Wells' jig I got the usual tapered scrap edges that actually taper down to nothing. Turns out they make great wedges to use on the extension! Same material even. Just bolt on the neck at the right set and slip them under the fretboard until they are snug and the board is level. Clamp and glue with wax paper under. Then thickness sand a cross piece. Glue it in and trim the edges flush, sand and fill any gaps and it's done. It really worked slick.
Terry