Steve if I was you I think I would reinforce that end piece of the box if you plan to pull it around from the hook. You could easily pull the end piece off the box those are no load glue joints unlike a dovetail joint like a dresser drawer. They where not meant for that kind of outward pulling force which you will be applying with the handle. Beef the side section up with some 90 degree angle stock in the outer corners see drawing USE 30 min EPOXY and be neat then you should be fine.