So close, and yet so far...
I had to laugh at this as my wife's kitchen, the garage and basement are all parts holding areas for various projects going on at the same time. I bought a 1979 cape dory 28 in Dec "2011". Your blog has been great to read as I work on my similar projects, bow sprit replacement, backing plate under the bow, core issues in that area on deck, volvo diesel, etc. My boat hadn't moved in at least 10 years. Your dads book on Marine Diesels was also quite helpful, thanks for the blog.
Yep, it looks like these
Yep, it looks like these boats tend to have very similar issues after so many years. I hope your project is going well. You likely have already but I might reccomend taking a very close look at the bedding of the deck eyes your shrouds attach to and any nearby fittings (I have a holding tank pumpout on the starboard side) as well as the vent cowls (if you have them) and anything else going into the deck aft of the cockpit. I'm reasonably sure water entering through these fittings and seeping through the core is what doomed my chainplates. Interesting to hear you had core issues in the same spot, I had thought mine were an anomaly as there's really nothing nearby to let in water. Hopefully no one cut out the bottom of your cockpit as well!