Got the block and the pistons back from the machine shop today - CLEAN BILL OF HEALTH.
Block looks great... needs a little bit of a pressure wash to get rid of the flaking paint on the block (from the hot tank, I'm assuming). I didn't realize how much gunk/build up there actually was in the cooling chambers of the cylinders until it wasn't there anymore. The chambers look great now, could probably use a little pressure washing themselves. (I can still see a few rust chips inside... )
The block came back with what appears to be some pretty big scratches in the cylinders... I'm a little concerned because they weren't there before I took the block to the shop and now I'm worried that the block might not be usable.

Unfortunately, I'm heading out of town for the long weekend and won't be able to take pictures, etc until I get back.

...or maybe I'll try to snap a few in the sunlight in the morning before we leave, get your opinion(s).

The shop said the cylinder walls and pistons were still well within specs, so I can reuse them for the rebuild.