Since you say that the wood is a solid, one piece shape, I would guess that it's a custom molding. There are 2 ways that I would approach this. The first would be checking the catalogs of every structural foam manufacturer that you can find. With foam, the deterioration that is probably causing you to look for more material can be minimized in the furure. The second approach would be to look for custom millwork sources in your area. A set of blades for a molding machine are not tremendously expensive.