On the Trailer Sailor's forum
http://forum.trailersailor.com/forum.php?id=1 Charles Brennan has a cast iron keel Windrose 18. This winter (he's in FL) he's been stumped by problems with his keel alignment and it sticking when cranked all the way up. He's tried all kinds of shackles and splices of the cable to keep the keel as centered as possible when bringing the keel up. The long and the short of it, when he finally decided to refurb and refinish the cast iron keel, when he cut back the glassed in pivot bolt from the last time he replaced it, he discovered that the keel bolt was not just bent, but broken. He also had used 18-8 SS, which can be almost any crappy rusty SS formula... This time, he replaced with a proper 316 SS bolt. You can search over there on his posts if you want to research how he figured this all out over the past 6-9 months or so, but I gave you the synopsis.
Yes, swing keel boats do have some limitations, mainly that they need to lift in some secure manner, and they need to pivot in some manner. But there are a crap-ton of swing keel boats (I'm not talking stub ballasted keel with non-ballasted centerboard like my O'day or a Precision, I'm talking real swing keels used for ballast,) like, for example 14,000 Catalina 22s sold. They all use a cable to winch them up, and as long as you keep on them for maintenance and keep an eye on your winch not rusting out, you cable wearing out, or your pivot bolt wearing out, they work just fine. Now, there are plenty of other swing keel boats that use a screw winch for the swing keel, for example the Beneteau First 21 and now First 22, and other European boats. And they work fine, too.
So, while I prefer my stub ballasted keel with centerboard, there's no reason to hate on a decently designed cable operated swing keel that's shown a serviceable history in the past. (Yes, after 30 years, I should check the Delrin pivot on my O'day centerboard. I know, but it seems fine!)
I think you are at a reasonable service life for your Clipper, and doing the pivot maintenance with good quality 1/2" or whatever 316 SS bolts, and making sure the cable is good with a decent sheave, you'll be due for another 10-15 years of reliable use.