Hi. I have a wonderful C-Dory 23 but need to replace the gaskets for the rear hatches that house the batteries. The old gaskets are leaking and we can't find the right size material to replace it. Called C-Dory and they said they don't have what we need. Any thoughts as to where we can find gasket material to make new gaskets for our boat? Thanks for any help you can give! Best Burt Brewer