I asked my mother to sew a cover for the box and this is what she came up with. All I asked her was to make it removable just in case I needed to wash it. Thomas has claimed this as his toy box and I spend a good part of the day putting the blocks back in just so he can turn it over and dump them back out.
I would like to figure out how to add a lid and use them to store DVD's and allow them to be stack-able. I will let you know what I come up with.