This page has a whole bunch of pictures, so if you're on a slow connection it'll take a long while to load.
Here I have scanned copies of original GM sales brochures, magazine articles, and other bits of "automobilia" from 1976-7. This is the vast majority of the Chalet/Casa Grande-specific stuff, but there's lots more general Blazer, Jimmy and Suburban brochures (and more) on my Brochures page -- see the Links section. Many of the Recreation, Blazer, and Four Wheel Drive brochures list the Chalet only briefly, so I've omitted them here.
The Chevy manuals are still in print, so I can't post them in their entirety. You can order them from Helm, Inc -- try the following direct links for 1976 (Item Number 460237), and 1977 (Item Number 460254). They're currently (June 2002) priced at US$20 each plus shipping.
The GMC manual is not currently available, and the cover scan comes to me courtesy of Doug (content is the same as the Chevy manual.) Should you know of copies of this manual for sale, please let me know?
I do have an online version of a Toyota Chinook owner's manual, which is fairly similar to the Chevy. You can see it on the Brochures page, by clicking on Chinook under all the model years.
Reprinted in the Motorbooks title Blazer 1969-81.