In the end (by the time I'd grown enough stubble to test-shave) I'd finished 2 new razors. One just polishing, one making and pinning new scales.

From not cutting arm hair at all, I did the following, all on a 1k King waterstone with light lather (except the last few strokes). I like using a bit of lather because it leaves a more visible trace of where the razor is contacting the stone properly - this is probably more useful to newbies like me than to people who can feel where the blade is making contact.

6/8" half-round half-hollow Joseph Rodgers.

Applied magic marker
25 x-strokes, moderate pressure
25 circles, moderate pressure
25 x-strokes, light ... at this point it passed the AHT along about a third of its length (near the point)
25 x-strokes, light ... now cutting (but not brilliantly) along the whole edge
10 x-strokes, light, with thick lather ... seemed to be good AHT all the way along. Nice 'suction' feeling against the stone.

4/8" Kropp square-point full hollow (pics here):
Magic marker
10 x-strokes, light
25 circles, light, ... AHT passed just at the point
25 x-strokes, light, ... AHT passed except for heel
25 x-strokes, light, torque to heel end, ... AHT passed except for heel
25 x-strokes, light, torque to heel end, ... AHT passed
10 x-strokes, no pressure, with thick lather.

In both cases the sharp edge gradually extended from the point to the heel. Is this normal, or is it a sign that I'm honing unevenly?

Both were then finished with stropping - 50 newspaper, 50 denim, 80 leather.

Test shaving - half of face with Kropp - cut quite well, but could be better. Didn't exactly burn, but some irritation during the shave, quickly fixed with Nivea ASB. Half of face with Rodgers, didn't cut as well as the Kropp, and irritation was worse (maybe the blades were about the same sharpness/smoothness but the heavier weight of the Rodgers caused this? Don't know). Still, not as bad as I expected.

Because of the burn I decided to do the second pass with my regular SR, and because I was thinking about honing not shaving, managed to cut myself. 2 months ago I couldn't spell noob, now I am one!