Here I have a project I made back in grade 11 for a metal art class. The overall dimensions are 3″x3″x3″. I really enjoyed making this jewelry box because it is very unique experience working with glass since accuracy in your cuts is absolutely critical for a good fit between your pieces. The lid to the box pivots on welding wire fed through copper tubing that is tinned to the lid. I would suggest keeping the design for the walls of your box simple so that the dimensions are repeatable.
Thanks for looking!