Need a 60's vintage 4 7/16" Bronze Rudder Pin

I'm taking the first steps on a 60's era Sailfish restoration but it turns out that the rudder I've got comes from another boat with a newer style 6 7/16 inch Rudder Pin (at least that's what I think it's called, see the pix) while the rudder attachment on the transom is build for an older 4 7/16 inch part. Does anyone have or know of a source for the 4 7/16 inch part? Or maybe you're willing to trade a 4 7/16 inch part for the newer 6 7/16 inch version?