I ended up using pressed wood and cut the shape of the form then used epoxy to attach the form to the wood.
I will not be able to reuse the straps for a hold-down but I have some very stable forms now to hold the boat on the jig upside down.

Been a busy weekend most likely will not make much more progress I had to go down the RCI Allure of the Seas cruise ship to work some today. My first time on the Allure what a cool cruise ship