I would disagree with what a lot of people commenting say. If the boats free, and you can do the work on her, that it can be a good deal. If howevor, you are not technicaly minded, then forget it. If the boat is not fully equiped, forget it, a new set of saild can be five thousand, i got a secondhand main for the irwin i had, for 1600, it was going to be 3000 new, a winch can cost an easy thousand, but if the keel is the only problem, ou are talking a few hundred in fiberglass gel, and matt, plus, the wood stringers, I would unbolt the keel, drop it, and that is (cant remember rightly) but about five thousand pounds, maybe four or three minimum) then jack the hull back into position, from inside, and outside, then glass it all with tons of glass, thirty dollars a gallon, and you will use easy ten gallons. Plus matt, same amount of money again. Then you have to come up with a way of lowering that keel, then raising it back up, probably easier to build a frame to hold the keel, and raise and lower the boat, with a lot of friends, and several ten ton bottle jacks and a jig built round the boat. Its not like a car, where you can simply attach a ram and push things back into position, you cant push that keel back into position.
I think though if you are getting the boat for free, and you have time, and skills, you could do it. If howevor, you have to hire a skilled man to work on that boat, you could very quickly be out thousands. Even taking the mast down, to transpor it, could cost you six hundred for the hire of a crane, that is the only way you will get that mast down, plus a few thousand to move it, so you leave it where its at, and pay a monthly fee, then travel cost to and from to work on it.
I would say, if you are carefull, and you have some friends to help you, and you were techincaly minded, and able to follow instructions, you could probably fix the keel for less than five grand. I would say between 3 and 5. Sturcturaly, you can make it stronger than it was when it was built, but you will probably never get the angles right, keel will be slightly off, how much difference that will make, i dont know.
Either way, its a big job, and it will take a lot of time and money, and as someone else said, take the boat, part it out, then take the rest to the recylers, i dont know if the keel is lead or cast, but either way, you will get quite a few bucks for it. All the fittings alone, ebay them, mine had self tailing winches a few hundred each.