Forgive me if you've done this already, but I was thinking you might get a lot of help from Island Packet's customer service. For sure on the actual chainplates and other rigging, and for sure on replacement methods. They may even have preferred riggers in your area that work with their dealer network and such.
I spent a number of vacations cruising with my friends on their IP 29 over the years, upo and down the west coast of Fla, and even a rendevous in Eleuthera during their 3 month cruise in the Bahamas
Anyway, I was always impressed with the factory support no matter how old or how many owners a boat had... each boat is like part of a large extended family.
Anyway, I think the staff from IP would be delighted to hear from you, so I encourage you to give them a call or email and get their input and whatever references they may want to provide. Good Luck... congratulations on your choice of sailboat.