RE: Lets try a splitter board/mold
Next I took the splitter board off the mold being careful not to release the wing from the mold half. You will need to clean all the gook from the edge of your wing plug ( remember the tub and tile caulk ) It cleans up eaisly though. Then you will need to wax and PVA as you did before and lay up this half as before. When dry cut the edges all the way around your mold and apply the frame to the new side. Try to avoid the temptation to remove the plug until you are all done.
#1 The mold after second half was all trimmed and frame is lightly clamped in place to dry.