In my past life of commercial photography (29 years), there was always a need to cut new inserts for the case of choice at that time, Zero-Halliburton. Diced foam wasn't known of then, so you would take the insert and put it in a deep freezer overnight pre-marked where the items needed to be placed. Then the next day you would take the frozen insert and with a serrated knife slice out the pre-marked shapes. The results were extremely precise and much better than anything you would ever get using diced foam today.Very nice!
So what do you use to cut out the foam?
I was just about to go out and get a Pelican gun case (thanks to the OP - this is a GREAT idea, by the way), but Kevin's post made me realize that I do pretty much what he does... I never bring all my cases (or rockets) to a launch. The volume of space would be significant, even with my (small) trailer. For storage, my 29/38mm cases fit in divided organizers (attach #1), 54/75mm fit in tube socks, and 98mm in rifle sleeves (attach #2). With 54mm and up motors, I usually have the motor decided in advance, and they often travel to launches in the rocket they are scheduled to fly in.I started out with the gun case route, when I realized that it's far too much bulk, especially as the number of cases increases.
Instead, I had my wife sew flannel sleeves and I keep the cases in those. I then put the cases I need for a given day in the bag I use to haul parachutes, or in a bucket, to take them too the launch.
I never haul all my cases, anyway -- far, far too much to take, when I won't use even 1/4 of them at any given launch.