Is this 440 block worth going any further with?

Hello,

Well, I had some bad news today. I took my $80.00 1976 440 Craigslist block already bored to .020" over when I got it, to the shop last week for machine work in anticipation of boring it out to .060" over for a 512 440 Source kit build. They contacted me today and told me that they cleaned / baked the block, it passed magnaflux inspection, and that they rough bored the worst of the eight holes to .050" over and it still has rust pitting on the walls where standing water from storage corroded it. I told them to stop the work and paid the machinist another $60.00 for his services and took my new $140.00 boat anchor home while I decide what to do next.

So the questions I have for all of you is how big of deal is this minor pitting and spotting, should I just look for a new block to start with, or should I spend the money on rough boring the rest of the seven holes to .050" (a gamble at best, approx. $25.00 a hole) and sleeve the damaged ones (approx. $100.00 a hole)? He said the leftover rust pits probably go down another .020" but I shouldn't go past the advisable .060" on a 440 block. I have included pictures for review.

Thanks,
Brandon