John,
The curved cross-section you observed is described in USPTO patent number 6718962. The named inventor is OL Adcock. John Harvard now of Dryad bows is noted to have signed a declaration in 2003. I have no information on who contributed what to the invention, who owns the IP or what licensing or other agreements may exist as we are at the limit of my research and knowledge on the matter.
Cool bow in any case.
Rasyad