I'll take a guess about it. It appears to be a 1962
Ohio built 24' tandem axle Airstream with a custom 2' longer Flying Cloud floor plan in place of the standard Trade Wind Twin or Double bed floor plan. The serial number indicates this is a 24' trailer, and I imagine if you ran a tape measure from the back bumper to the front ball coupler it would read very close to 24'. But the single curb side front louvered window suggests a 1962
Flying Cloud floor plan. Another photo of the street side windows would be very helpful to confirm this strong possibility.
I imagine a customer wanted the Flying Cloud floor plan on a tandem axle chassis, and had to order a 24' long chassis to make this happen. In 1962
, tandem axles were an available option on the 24' Trade Wind (and standard on longer trailers) but not on the 22' Flying Cloud. So, the solution appears to be a Flying Cloud type floor plan on a 24' tandem axle chassis.
The customer also ordered the upgraded International interior trim with its many nice standard features that were optional on lower trim Land Yacht trailers. The "I" prefix to the serial number, the tubular frame around the serial number plate and the printed "International" name on the serial number plate all identify this as the highest trimed Airstream trailer. The Flying Cloud name badge and the unusual window arrangement on the curb side tell us this is a very unusual custom made Ohio built Airstream with a slightly stretched Flying Cloud floor plan inside. Neat find!