Nice wagon. Everyone has a Vista because that's what has survived. Having a flat top Cutlass is cool. I also thought the wheelbase was a bit shorter on the Cutlass. I've been known to be wrong.
There were actually two wheelbases used on the Cutlass and Cutlass wagons that year. The F-85 (offered with a 6 or a V-8, both coupes only) and Cutlass S models (all of which were coupes or convertibles) used a 112 inch wheelbase. All plain Cutlass models (all of which were sedans) and Cutlass Supreme sedans used a 116 inch wheelbase as did the Cutlass flat-top wagons. The Cutlass Supreme coupe and convertible, like the F-85 and Cutlass S coupe and convertible, as well as the coupe and convertible 442, used the 112 inch WB. In short, if the Cutlass/442 was a sedan or station wagon, it had a 116 inch WB. If it was any kind of coupe or convertible, it had a 112 inch WB. The Vista Cruiser had a 121 inch wheelbase.
The Cutlass wagon's frame is the same part number as the Chevy Elcamino. So if you need anything frame related like brake lines and what not, those are easy to get. This is what I was told at least for the 70-72.