Iron keels are not really the problem that some peple would lead you to believe. I don''t know about the Hunters (are they an encapsulated keel or exposed? I suspect encapsulated in fiberglass) but I have worked on a 70s vintage Shark 24 that had an exposed steel keel with a bulb at the bottom. A regular painting with bottom paint was all it took on a yearly basis. Yes, there were rust streaks by the following year and a bit of wire wheel grinding was necessary.
On a fiberglass encapsulated iron keel the iron is protected until you hit something hard enough to crack the glass. Then, just like an encapsulated lead keel, you have a problem. Water will get in and it must be dried before repair. his could take some time (weeks?). With iron it would be critical to ensure that it was dry before sealing it up. With lead it isn''t quite as serious.