New faucet is what I think you need as I do not think that you can get replacement parts.
Try West Marine I think they have them.
Easy to change if you can get under the sink. But if it's like my 2400 SCR then I think the fridg has to come out.
It's a Whale faucet.
1995 Maxum 2400 SCR 5.7 A1 G2 LUNA DE MIEL
1988 Bayliner 2455 5.0 IO (sold)
1987 Seaswerl 18ft C. Cabin 4.3 IO(lost in fire)
1976 16ft. Tahiti 2.5 IO (sold)