I picked up this IKEA Stainless Tower Rail in the As Is section of the store for $3, it's a steal but even regularly prices at $9.99 US the 31 inch one gives you over 2 and a half feet of space for punch storage.
|Attache Case - 18x12.5x 5.5
|Inside of case, dividers configured to fit large punches
|In the lid, a snap our tool holder, nothing added to it...yet
|Carrying strap, for the times you have to run with your punches!
I store all my large, extra-large and huge McGill punches in this 'secret agent' attache case. The interior can be customized by moving the slide out dividers as needed. At bit of old 'tetris' skills are helpful and was fun to put in place.