How about I measure mine and give you a table: (so thick so far back etc.) Could you grab some exterior plywood and a belt sander, (or pneumatic orbital)followed by a few coats of fiberglass and more sanding? I say plywood because the plies give you a depth guide as you sand, like a contour map, which really helps. I dont guess at this stage the weight/class legality is an issue? What would this cost you?
The std boards aren't light either.
I wouldnt try to sail those hulls without boards. You wont be able to go to windward and the boat wont behave at all at low speed. Just be a bad experience. Any king of board would be ok I believe. (dinghies rely heavily on boards that are just that, boards, and without them the won't do anything)
Let me know.