So time to finish the lid. After screwing in the hinges into the box dados, you take the box and put it up on supports/blocks that are the same height as the box. The rough box lid is cut larger than needed. You then screw in one screw per support, then test the fit. Mark out the top so you have 1/8” extra in the front, and 1/16th in the back.
After that, you cut the top to size, finish screwing in the rest for the hinges, and double check the fit.
Once that is done, you attach the top part of the lock back with identify where the lock goes.
From that, you set the lock in place, trace around it, then use a knife and straight edge to layout the mortise where the lock goes in.
With that done, you use chisels and a router plane to clean out the mortise to the correct depth.
Once you test fit, you can screw it into place, and the then test the lock one again, just to confirm.
All that is left is to cut and install the skirting on the lid, clean up the box, and then apply a finish.
Close to the end!