That is a tour bus used in the Columbia Icefields in Canada, about 2 1/2 hours from me. It is manufactured by Foremost Industries
www.foremost.ca I've looked at it about 50 times and still cannot remember whats under it for power train. Brewster's own's the coach along with many other successful businesses. There are more of these beasts in Churchill Manitoba, they are used for safely checking out polar bears.