Can we presume your "Spare tire winch cable broke" between the winch itself & the plate attached to the end that holds up your spare? Chances are there's more than enough cable left to allow you cut off the exposed rusted end & reattach the end plate.
You can also consider the concept: Why buy new when used will more than do? Note that the "Spare tire winch" from other FORD's (like F150) may be interchangeable.
Sometimes, the end of the cable will rust and break off. That's easily fixed. What is more common is the winch mechanism, which is a pair of plastic gears in a riveted, pot metal case, strip. That is not fixable.
An NTB tire store stripped the gear in mine and refuled to replace it. I bought one from a junk yard for $25.