Have you tried Hamilton Marine for the acorn nuts?
I would be inclined to use a similar metal for the nut, even though it's not submerged.
I love Bronze.
I got an Old Fat Boat
She's Slow But Handsome
Hard In The Chine, but Soft In The Transom
I Love Her Well, And She Must Love Me
But I think It's Only For My Money
. ..... Gordon Bok