The one in the Detroit ad in post #2 was on a non-original 2wd '79 Blazer, and it sold on the same day, while the Saginaw one is now listed in the Detroit section here:
http://detroit.craigslist.org/okl/cto/1703168781.html
That one is serial #1551, and the seller has been deleting and re-submitting his ads, so Google search for Chalet #1551 if the link doesn't work. He's a member of our Yahoo Chalet owners' forum, I might ask him to keep a constant ad.
They are definitely rare, but tough economic times causes more guys to be selling them, I had to create a
Google map of ones for sale just to keep track of them. A couple of years ago, there might have been as few as five for sale all at once, now there's been around 50. PM me for specific vehicle info.