If the original paint were intact, I would just paint over it, but the paint is splotchy, at best. I have a Dreml tool, but it may be too small for the job. The crate is approximately 24” X 18” X 12”. The handles at each end are spring loaded. A spray paint remover would be best. This thing is plywood-lined, so unless it is crushed or incinerated, it will last a good long time into the future.
A proper cleaning should probably be done outdoors, where the stripped paint can be contained in a disposable plastic dropcloth.
After you have restored it, what you put in it will depend on what you want to take out of it, and what you want to do with what you take out of it. For instance, photographs or records.
Picture opening it and removing something and then ... what?