I'm not sure composite chainplates could be retrofitted the way mine are made. They were planned from the start with fan shaped recesses in the topside core. Before the deck was laid a solid FRP block extends above the sheer line and a stainless pin laid on top. Everything was then wrapped in uni strips that fan out to fill the recess inside and out. The pin was removed and gaps were ground out for the toggles.

The D1 plates were a bit more of a challenge. They were fabricated off the boat and installed after the deck was installed. They are basically inverted tees with the cross forming a flange that is fitted to the inside of the topsides and angled to keel the pins perpendicular to the D1 shroud. I had to build a jig/mold for each side to keep the shape exact. Once in place they were heavily glassed to the deck and the topsides.