Quote Irish:
I know Justis does not use the outer large tube but I find that is a weakness in his cases as you can squeeze the case out of shape quite easily. Whitten looks like he uses a injected mold from what I can tell from his site (although none of the pictures are close enough for me to be sure).

I have all of these cases. The Justis case doesn't need anything between the tubes because the outer leather is so thick. He does it this way because the interiors are replaceable (Jack will put in new interior tubes and probably sells them too). While the Whitten case is stronger, the leather is glued directly to the foam so the bad thing is if the case gets dinged, it causes a dent in the foam which is therefore visible in the leather.

Foam core cases are difficult because they're usually molded to fit a generic stick, and if the holes are too tight, or have a different taper, they can get stuck. Whittens holes are large, so the shafts disappear. Porpers are tight, so the top is hard to close and the shafts can get stuck when pushed down. The advantage to foam core is that the finished case is pretty light and very strong.

I believe most of the case makers outsource the foam core injection to companies suited for this, then sew up and assemble the cases in their own plants.

Chris