Chainplates on a Cal 2-46

[Little Bones]

Hi there, I am looking for some advice on chain plates on a Cal 2-46.
I am looking to buy one and the seal is near closing but I discovered something in with the chain plates that causes me some concern.
It looks like part of the stringer on the starboard chain plate has been modifies, maybe due to some rot inside the stringer.
And of course there is painted stainless steel and bolts and rust.
If anyone has any input that would be appreciated, even a picture maybe?
Sorry, in the photos below the rust appears to be defying gravity however that is because the picture is upside down.

Thank you,
Little Bones