I noticed your post just now as I need a new plate as well. Yours is simply a black white sandwich plastic plate made at a trophy shop for the boat manufacturer (or maybe they had their own engraver and made it themselves).... easy and cheap.
Mine, OTOH, is official Naiad metal plate (with their logo) but even that
they can't supply (and seem proud of that fact...like how dare I ask about something made way back in 1993 when dinosaurs roamed the earth...
...meanwhile they probably had hundreds of them in the late 90's and threw 'em in the dumpster during spring cleaning), so I will probably have to go the trophy shop route myself.