I had to do some eBay searching to come up with it too. seller id is rehenberg.

He's got it described as Mopar Fuel/Gas tank leak seal kit. As was pointed out, the listing doesn't include wagons, but the seals are the same.

I ordered one for mine and it came fast and looks like it will work fine. Good part about this kit is it includes the one for the sending unit as well, which I hadn't even thought of.

Good luck with the wagon!