I recall that the chainplates on this model pass down thru the deck and are bolted to bulkheads inside. The original material was SS, and can be weakened by unaddressed leakage from a failed seal where it passes thru the deck.
Even if the original SS is not noticeably affected by corrosion, I would guess that passage of time might indicate a need at some point to replace. Maybe.
IF you get 40+ years out of the originals, it seems reasonable to replace with SS. If you want more freedom from corrosion replace with Titanium.
Just for a hobby and getting some experience with higher-tech parts, you could make 'em out of carbon composite, but this might take more money and time than most of us would devote. Do you have access to the engineering and layup expertise to be Real Sure that your composite replacement will be as good?
And, to address the "elephant in the room" since we are considering a 35-2, have the existing chainplates been pulled and the deck coring in that area filled in with thickened epoxy? Are the interior bulkheads 100% solid with zero moisture damage? This is important no matter what you make the chainplates out of.
Keep us in the loop. Interesting stuff!
BTW, nicely produced video, on the whole. It left out the begged question of why water was allowed to drip down around the deck penetration for what must have been years or a decade. Besides the wasting away of the metal there was a lot plain old rust evident.
As we found when we pulled all of our deck hardware off for our recent re-fit, at about 30 years even the best factory sealant is starting to fail. The lady in the video was perhaps not aware of this, and may be starting to have more hardware leak/corrosion problems all around her boat. (?)
