Hey Paul....well I did some checking on "wide body" and found a few things to share.
First the blue/gray factory owners manual that came with it has huge letters on the cover that say "WIDE BODY LAND YACHT PUSHER by Airstream". Tried to get a photo but my picture file was to large to download. Will work on that
Next in the contents page, Section B has a detail listing called "Wide Body Limitation Loading". Its lists the following for this type unit:
Net Carrying Capacity - 1960lbs
Unloaded vehicle weight (full fuel) - 19,040lbs
Gross front axle weight - 8000lbs
Gross rear axle weight - 13,500lbs
Gross vehicle weight - max allowable weight - 21,500lbs
Gross combined weight - motorhome plus cargo - 26,500lbs.
Mine was built on a Freightliner chassis with Cummings engine. Some older units were on Oshkosh Chassis. Records show Freightliner bought the Oshkosh Plant in Gaffney, NC in 1995. My AS frame was built in April 1997 and shipped to Jackson Center where the body was added and finished in July 1997. First owner picked it up on 8/1/1997 after it was delivered through a local Airstream dealer.
The sale brochure for 1997 also has it identified as Freightliner Chassis 228" W.B. with air suspension. The exterior length is listed at 35' 10" and exterior width at 8' 6" or 102" wide. Guess that's how they came to finally call it the Wide Body.