The top of the lazarette needs to be in two pieces - a single piece would be too large to swing open via hinges and still clear the tiller. I suppose I could have built a removable top, but I thought that would just get in the way when futzing with the anchor.
In order to have the two pieces swing open, one to either side of the boat, I found some regular butt hinges. By adding a thin layer of plywood along the seat tops I created enough height to perfectly allow the hinges to be mortised in flush. This would also give me a double-plywood thickness lazarette cover which could stand up to some anchor abuse (yes, I still overbuilt this).
In order to mortise out notches for the hinges I built a little guide for my router.
Closeup of a cleaned up mortise
The other thing I did was to cleanup the various cleats. I coated them all in epoxy and sanded them down again to get them smooth, applying fillets in a couple of places as well in prep for adding fibreglass later.
Top edges flat and ready for epoxy
After the cleanup, some of the mortises were a little too deep, which is actually perfect because I wanted to seal the edge grain plywood with thickened epoxy (and indeed later I’ll even drill/fill/drill holes for the hinge screws to make sure they’re biting into epoxy and not edge grain plywood).
The last step was to actually fibreglass the inside of the lazarette locker. Again, an anchor and chain is going to be rattling around in here, so I wanted to make sure it was extra tough to stand up to the abuse.
Note that there is still an air gap in the gutter underneath the front edge of the lazarette and the cockpit sole - water will be able to drain through here into the footwell where it will get dealt with like all the other water that gets into the boat.