I have glued the floor onto the hull. Very messy job, with thickened epoxy fillets. I got through about four pairs of rubber gloves. I hope I have filled the joints well as they are crucial to holding the whole boat together.
I will be putting fibreglass over the outside of the joints, so they should be strong and watertight. The hull is slightly distorted where the seat frame is glued in, but I think I might have broken a side if I had tried to move it around without the frame. The whole thing is much heavier with the floor in place.