Thanks for the update and explanation for the alien blocks, @Tongo-Rad. They still look like an afterthought / trouble shoot solution to me, but what do I know...My Ellesmere is back from Blackline Marine.
It's a challenging time with parts availability these [COVID] days so unfortunately, they had no supply of compression fittings to either add a nut onto the existing bolt, or replace the fitting with an entirely with a new one. Their solution instead was to replace the skeg cable, reinsert the housing into the fitting that's in the skeg fin, seal with Sikkaflex and then apply fibreglass over the whole area resulting in what they felt would be bomb-proof setup. I was hoping for a more serviceable solution for the kayaks later years but on the flip-side, it'll be difficult for that area to be compromised
I think the Boreal Design Baffin has the same setup but not sure about other Boreals.
I think vintage of the kayak plays into the installed skeg system as well. The Baffin and the Ellesmere that I've worked on, and that spring to mind right now (I don't remember their exact age, though), have a different blade pivot point / mechanism.