One suggestion
Since Ericson Yachts went away, along with the tooling for your model, in about 1990...
one suggestion would be to have another owner make you a quick mold.
He'd need to take his lid home and cover it tight with Saran Wrap, and lay up cloth and resin to make the mold. Use enough layers to prevent flex.
You could then take that mold and wax it, lay up cloth, coring, and cloth... and have your lid. You'd still have to paint it to match the deck.
As for that distant friend that fabs the mold, send him a check and/or a
very nice bottle of single-malt.
Plan B might be to lay up your own, with temporary curved "ribs" over the anchor locker. Use thin veneer sheets and epoxy to get the slightly curved surface to match the fore deck. Maybe.
Cheers,
Loren