Mark, towing a FW is more about payload, than weight being pulled. Without the 7-bolt wheels, E-rated tires, an F150 can easily be over rawr, and tire rating.
A dry pin of 1300, will be at least 1500, with just regular load in FW. You have to add 200#s more for the hitch, plus anything in truck, family, gear, etc.
When you look at tire loading chart in the truck, it will tell you how much load, this truck, can safely carry.
If you like the FW, maybe buy it, and get a used 3/4 ton to tow it. If the FW has been cared for, it could last another ten years, with continued care.
Jerry