M_Boats: Teak or Teak Plywood

Hello, Does anyone know a good way (or place) to get a hold of some small teak wood pieces (or teak plywood) to use as backing plates for the transom hardware on my M23. Teak plywood is currently used on the cockpit side of the transom on my M23 and is showing its age. I need 5/16" thick pieces. I need 3 pieces about 6" x 6" and several 1.5" x 3" pieces to give an idea of the size. Thanks! Gerry