I think there has been some bad information introduced into this thread that has lead Mike astray.

There was a hand drawn diagram that indicated that the chainplates for the lower shrouds are embedded in the cabin top.  Though I have not (yet) had to replace my lower shroud chainplates, I can nonetheless say with a great deal of confidence that this notion is incorrect.  The lower shroud chainplates are embedded in the cabin side walls.

I hope that clarifies things.

Peter Nyberg
Coventry, CT
s/v Silverheels (1988/2016)