It's your block. They can't help how deep the rust is.
Many 283's will go as much as .125", so .060" is a walk in the park. If the over bore is now at .030 or something like that, try and bargain with them, and get it bored to the next size.
The rust pocks, if they are minor won't cause much issue. I know, I've got one that I run that was similar to yours. Of course, from the pictures, it's a little tough to tell how deep they are. Mine only had a couple of small spots.