Sorry to hear about your loss... Awesome looking wagon, I love it. And a hyper pack slant six. Wow!
I hope that you get it back in the condition that it was when it was stolen.
Keep spreading the word. It will be easy to spot as it is such a unique and rare car/wagon. I've heard that some people that steal cars like this sometimes ship them out of the country to avoid getting caught. Keep an eye out on the coasts and shipping docks also. Good luck finding it.
The guys who did this should be gently strung up by their necks from a tree and used as a pinata - where you get to whack them to death (that's why you gently string them up - you don't want them to have a nice quick death, but a slow painful one).