Since you mention the compression post- How is the deck area around the mast? Is it showing a lot of deep, radial cracks? Hopefully not, but if so, it could indicate problems with the compression post.
I'd be interested in seeing photos of the shoulders/chain plate water damage. Except for that area, it sounds like the boat is in pretty good shape.
S/V Old Shoes
1973 Pearson 30 #255