Nice work Jake!

The boat I just picked up has a homebuild trailer with an angle iron frame for the box, the frame is covered on top with plywood. The box itself is a plywood "drawer" with two handle pulls you simply slide out the back. Advantage? You don't have to wait until the boat is off the trailer to access the box. The aft mast stand slides into a box beam welded to the frame and doubles for keeping the box from sliding out on the road and a hefty bit of metal to slide a padlock through. Will post pictures soon.