I've just done the same with my Night Heron S&G. Currently cleaning up the inside. Found some bubbled fibreglass in the stern with rotten ply underneath. This was the first kayak I made and the interior fibreglassing in the ends wasn't that great. Good to take the top off and get to fix this before it got any worse. Also cleaning up a kajaksport skeg I installed through the rear hatch a few months ago. Once again, bit messy when I got to see it in full daylight. I'm also thinking of lowering hull/deck a cm or so. Useful thing - taking the whole top off:)