A stock Mooradian
fits. It's a little tight but it works without stressing the zipper. I think someone here had them make a custom bag for his JC. Since they make everything in their factory in Boston the custom one might be pretty much the same price as a stock one. In any case (no pun intended) Mooradian is top quality stuff that works well and lasts years.
Just as a side note for air travel I was hoping that the SKB roto case
would fit a JC but I tried one today and it doesn't.