Leveling Rear Deck Question...

[BarnacleGirl]

I was wondering if any of you have some suggestions for leveling the deck on my 23'CC. I took it off this weekend to rewire, replace some fuel lines and to locate the two fuel senders in the rear fuel tanks. The front and rear of the deck is flush, but the center of the deck dips and creates an awkward slope, it is right about where the two supports go for the leaning post. I don't really want to get into fiberglassing, but was looking to fill the gap with wood splintz or some sort of compound since it dips in completely random places. Any thoughts would be much appreciated...BG