I found your post about rot in a Google Search for Invaders. You list the Frigate as being an Invader and it's my understanding that they are different boats, very similar, but not the same boat. Yours is a little bit heavier and the rudder is different.
That doesn't matter but what I keep an eye out is for Invader owners to make contact. There are one 3 of us that I can find and we are trying to see how many of the original 25 that were made are still alive. Here's my site if you are curious.
Relating to your post. Did you get the rot fixed in the bulkhead? All of my shrouds are bonded to the hull and none of them are chainplated to a bulkhead. I had a rig on a Columbia come down once when the chainplates pulled out of a rotten bulkhead. It was not pretty. I'm glad I don't have to worry about that now. I hope you got your fixed. It's a mess if it pulls out.
I'd be interested in seeing photos of your boat if you have any. It looks very similar to the Invader.