When I needed to match an RV surface, I found SolidSurface.com to be the best price online. They show your Corian
here. Any local fabricator should be able to make a new surface. Or, do it yourself. You can purchase the adhesives from SolidSurface too. I made a countertop to match my RV with little trouble. I cut the material with a track saw using the specified blade (a TCW - Triple Chip Grind) blade, and glued the pieces together with the specified adhesive. The whole
project ended up looking like a factory addition.