Okay, da deed's bin done
The right pedal, which is the suspect one, had obviously had water get into it as the grease had turned brown and it looked pretty mucky. I did have a fall on that side about 18 months ago but never detected a bent pedal shaft. Both shafts have black marks on the bearing surfaces but seemed smooth enough.
Quarter inch drive sockets fit into the housing quite nicely. I was able to get one socket onto the cone nut and one onto the locknut ... just not both at the same time. This made adjusting it easy and doing up the locknut an interesing exercise in jamming a small screwdriver between the cone nut and the housing and hoping for the best. No swearing but I do wonder if I've done things up tight enough.
Neither pedal had the requisite number of ball bearings - shimano are getting cheap on us and I wonder if this explains the black marking on the shafts. Neither pedal had the same number of ball bearings either, and both had an odd number of balls ... so I put the larger number on the inside bearing guessing that this is the bearing that does the most work. Thinking about it now, I'm wondering if I had that back to front because the outer bearing is probably larger. I'm not pulling them apart now.
The inner bearing is about an inch inside the housing which made getting to it fun, but a greasy screwdriver soon had the balls in place.
Just a fiddly, annoying job. Having the right tools would make adjustment easier but I think I'll get away with my efforts.
And following with my principal of always finishing a job on a positive ... I'm not test riding it till tomorrow
Richard