Scott,
I used 1/2 inch marine plywood. I don't know what kind, whatever could be had in St. louis. I added an eigth inch of glass on both sides and redid the tabbing on the forward side (Although, I have no idea what the foreward tabbing was for sice the structure was all on the aft side.) Put it through some tests last year. One six mile beat in 15 - 25 with 1600 pounds on the high rail and the other in the water several times. Didn't move a bit. I think the glass on the aft side is all that holds 'em up when they get like your's is and mine was. Send and e-mail address and I'll sen pictures.
