Welcome to the forums!
1072 Trade Wind (twin) dry weight is 4140 acording to http://www.airstream.com/airstream/p.../weights-1.pdf
Add water, food, propane and stuff. Your Explorer also has a short wheelbase. I do not think I would want to tow with that setup. As far as the Trade Wind goes, it sounds like alot of work. You have not mentioned the big money items yet, the floor and the axels. I looked for my Airstream for almost a year, the first one you see may not be the right one. BTW, when the owner says that all of the appliances work, make him show you
This document http://www.vintageairstream.com/rr_t...condition.html
is a good guide of what to look for when buying. Good luck with your search!