Those Anvil cases are sexy!
I might be able to get away with using some sort of production level case, even one that was made for something else, to safely store those assembled double pedals in.
I looked at my DW 9002s tonight. I don't expand the connecting rod out too far. I think from exterior most frame to exterior most frame of the pedals is something around 28/29". I think the base plates kicked em up a little towards the 29" mark. I might double check tomorrow.
On the one had a custom Anvil case might cost a kidney or something, but on the other had, it is one of those buy one and done sort of affairs. You would want to be smart about the pedals you buy it for though. Be pretty damn sure that you have the pedals that you like playing. You might want to take into account allowing for extra room if you ever decide to go with a different manufacture's pedal, or long boards.
I am going to get something. I wanted tonight to be the last night that I put my expensive pedals into the same case as all my other hardware.