Re-beveled the glass, doing it properly this time. 100 grit waterproof paper, sprayed the glass down with soapy water, positioned it just hanging over the edge of my bench, and worked for 45 minutes. End result: proper bevel about 1.5mm wide, at a nice 45 degree angle. This should last a little longer. Used a lot less sandpaper than the previous attempt too.
Since the rest of the family had an early night, I had time to kill, so did a bit more grinding. I’m trying to change my action to diametral strokes, overhanging by just over an inch on either side, but I’ve learned something about muscle memory: Whenever my attention wanders, I find myself drifting back to the wide ‘W’ I started with. Hopefully I’ll conquer this before I get to the fine grinding. The unground hollow in the tool is now about half the size it was Saturday evening. Visible progress is a wonderful thing!
Before packing up for the night, I measured the depth of the curve with a straight-edge and a set of feeler gauges to be 0.60mm. This is less than I had before, but I expect the bevelling is to blame – by necessity it has lowered the height of the edge, so the reduced depth doesn’t affect the amount of curvature.