I agree about the plates. You have two more under the winch on either side of the centerboard trunk to inspect the shaft for the cable block that guides the centerboard cable through the trunk. This block can stop spinning and get a groove cut into it by the cable. You can see the block if the boat is hauled out and you lower the centerboard and look up into the trunk.
Air draft is 33'-6". That's the important measurement, as a lot of bridges are 35' at mean high water.
Rehoboth Bay/Indian River, DE
S/Y KJ, Helms 25