Great news! We're back in business, I received the new block today, and by a quick look it appears to be in perfect shape.
I'm going to slice and dice the head too, and see what it's made of
I got the wiseco pistons wrong, though. There isn't enough material to machine the flat head pistons into sufficiently low comp. I'm going to have to get them changed to dished pistons. Just a minor setback...