The problem is that the sloping edge of the fiberglass cover closes behind the top crib board. If I install the weatherboard flush, it will not meet the edge of the crib board..I don't think it will weatherproof. My boat is 1985. We bought the boat used & we are doing some upgrades..I do not know what year your model is, so on my new style model starting with the year 1986 the weatherboard trim is mounted flush on the front sloping edge of the sliding hatch cover. Keep the top edge maybe a little high of level, if you get it too far down so the wood will almost touch the cabin roof you’ll probably step on it and break some of the lower edge off. It adds a little extra protection but, I think it’s a lot more cosmetic.
The bottom of the fiberglass does not clear the top crib board.What prevents it from extending far enough to overlap?