So, over the past few weeks, I’ve been digging out and lifting the flagstones (most of the stones are about 1½" thick), in preparation for putting fresh gravel underneath them to raise the whole walkway back up.
Finished lifting the stone walkway between the house and the driveway over the weekend, as well as the front stoop. The last stone (right in front of the stoop) was the hardest, being about 3' x 4' and 3" thick (it’s an old lye-leaching stone). Rather than lifting it, I basically just shifted it about two feet away from the stoop using a 4' straight pry bar.
The stoop has been [mostly] repaired and put back on a refreshed bed of sand and gravel.
The lye stone is in place on refreshed sand and gravel, set higher than the rest of the path to make a low step in front of the stoop (which is about the same size).
The remaining stones have also been laid out. I’m not completely happy yet with the final height of the stones, so I'll be adjusting the gravel amount under them for a day or so before starting to fill in the spaces between the stones.