It might command more for a Ford/Mustang fan, but condition is probably the most important aspect of it. Be sure to take lots of nice pics of it (with hopefully at least a bridge camera, if not a DSLR).
Buyers lack imagination and will often assume the item is in bad shape if the photo is low quality. Maybe have a friend take the pics if you don't have a decent camera. And I'd post it on here, CL, Offer Up, local ads, etc..
The value is almost impossible to assess because to different people, it's worth either a little or a lot.