The 1979 Cobra isn't a really desirable car YET. As it stands I would say you could get anywhere from $1000-$3000 from it depending on the buyer. If I were you I would hold onto it and try to repair because chances are it will go up in value once people realize they're out there.
i have an 80 hatchback, that i worked on.
the 79 cobra is amazing.
if you part it you, you definetly make alot!
the ground effects, hood, engine, louvers, interior.
we are talking alot of money.
but... in the long run hold on to it, the fox body mustangs are making a comeback.
get it running, cosmetically nice, and you could get some serious cash, the 79 cobra is RARE. ill stress that.
god i wish i knew where you were, i would buy it RIGHT NOW..
i say keep it.