I was lucky enough to run into a German guy on Hood River a number of years ago that was driving a 1981 VW LT28 Westfalia Sven Hedin. It turns out he was interested in selling it!!!!!
I got a German title with it and did a nice little loop up through Vancouver BC, and voila, the US title was made.
The German campers have the propane inside of the cabin, not allowed in the US. There were two of the bottles, and when I sold the camper a few years later I kept one of them as they were pretty unusual in their design and size with a bunch of cool German language stickers on them. The VW LT Westfalia was like a super sized hybrid of a VW Vanagon and a VW Baywindow bus, of which I have both, so the big beast had me captivated for a couple of years.
I was unable to find a good mount until I stumbled upon the Hannibal South Africa website which showed one that looked like the right size. I exchanged a couple of emails with them and then gambled and ordered one from ZA. It was designed for a Defender, and I assumed it would need some modifications to fit properly. Turns out it fit the propane bottle like a glove and the only issue was that the Gwagen gutter on the rear slanted a bit to the side of the vehicle while the Defender was a level gutter across the back of the D pillar. It turned out to be an easy grind down and looked like it was made for the vehicle once it was done.
http://www.hannibal.co.za/Catalogue/Accessories
The bottle holder fit well in the space on the left of the vehicle opposite the ORC ladder. I had to get some Euro propane fittings to work with the bottle in order to run a line down to the camp stove on my rear table. Like the ladder, it clamps to the gutter and is held at the bottom with 3M Dual Lock tape.