I was actually able to get all of the inner bolt covers off. I don't know if someone had done a previous rebuild and not epoxied them. I am going to redo them with Locktite 2422.
I did a bunch of reading and talking to people, and general consensus was that these plates should be replaced as they are under enormous stress, especially in the salt. The baffle i am getting is from a freshwater motor. I will obviously check it with a straightedge.
I redid all the seals in crankcase as well.
I want to get block back together without any more water intrusion. If this doesn't solve it, i don't know what will.