Seems to me to be absolutely crazy to buy something like that to store accessories. My humidor has a set up very similar to that and, though it seems to have a lack of proper seals, it does otherwise do a very decent job of holding in the humidity. I am able to maintain a constant 65-70% humidity with minimal effort.

Especially with the Oasis electronic humidification system you should be able to keep a good, constant rH in that box. And - it really is not difficult to either pick up a replacement electric cord for the unit or make something that will work. I suggest you try and get the unit up and running and see how it holds the rH. You might be surprised...