Thanks for the page of links! Now I know what to Google. I'd been unfamiliar with the term "rubblestone." I'll check out those links. There's no sign of the foundation changing in the past 40 years--no changes in the way doors close or other differences in the 1st and 2nd floors with its post-and-beam construction. It's reasonably water-tight (some water has always leaked in at the base of one corner; it follows a trench to a sandy spot where it sinks away). I'm not so much trying to "fix" our cellar's foundation walls as to plug up air leaks and make it a bit more challenging for rodents to get in. Basically we hope to patch it up more or less the way the previous generations did. We just heard from the guys who haul in our firewood each fall--suddenly our cellar work has to be done within the next 5 days due to their schedule. Looks like we'll be stuffing fiberglass into the cracks again. I did note in some article links (just started reading them) that there's a danger in repairing only from the inside--I can see there's more to this than I'd imagined. Sadly, we can't afford a major (or minor) engineering project. The house needs to stay intact about 15-20 years (our maximum expected lifespan), which I think it will do. Thanks again!

one solution i was going to suggest was if it wasnt too many boards that had large gaps, was to install some very short pieces of floor to bridge that gap, which is still an option, just a matter of time and patience on your end. building out the base and shoe mouldings will achieve the same result.

"What is considered the 'normal' width for the gap?" I'm assuming you're speaking of a freestanding range? If so, a gap between 30 1/16" - 30 1/4" would be considered normal. The countertop sides should be perpendicular to the rear wall and parallel to each other, no matter what the cabinets are doing.

My take is the installer did a poor job of measuring. Can it work with that opening, certainly, but you will need to pack that opening in with some solid blocking but then you will need to figure a way to hide the blocking which kind of defeats the purpose of the custom ordering to fit the opening correctly. Up to you but I would think about making the installer reorder a larger window.