Sam -
The top plates are stock... no mods/polishing/paint. The bases are solid wood, with the curved bottoms routed using a template made of plywood (which was mocked up first in Adobe Illustrator and the curves were printed on paper and glued onto the plywood), and the grooves were routed with a small straight bit. The finish is just rubbed shellac (hopefully it can withstand the heat!) with some paste wax as a top coat.