Basically, you can do 2 things. Use the case or get the first generation case, they are long and flat. Or you can get some PVC, cut it and put caps on it. I would recommend then taping them together. If you are going to do that, I would just recommend the first gen case. The last thing you want to do Is chip and ruin your inserts.
Buddy of mine uses elastic shotgun shell holders from a belt or something, and places that in an old cd travel case (sans cd sleeves). Compact, and works really well from the looks of it. I think it only holds 4-5 inserts, though.
So I was wandering around in the local home depot and found these Screw storage containers and its rugged enough to stand up random drops and whatever else you may have in your gear bag that may harm your precious freak inserts.
these containers are only $3 each... pretty cheap considering it will save you the heartache of going to buy another set of inserts...