I am following this very closely as I have a very similar installation and need new chainplates on my boat too.

The question I have regarding bedding is that I am thinking that the bedding material is supposed to be something like 4200. But then in my mind we come right up against the issue that this seals the back of the chainplates from oxygen, and thus can lead again to crevice corrosion.

And then what about the hardware... again sealing it? If so, how? What is the best practice here?

Thanks