Torque setting demonstrated belowProgress time. 11mm box spanner (well, a 10 and 11mm box spanner, chopped in half) obtained and thinned in the walls so that it fits inside the end of the pedal body. Piece of pi$$ with an angle grinder. Same done to an 8mm socket - now passes down within/ inside the box spanner. Socket extension bar bought so that I can operate the 8mm socket with a torque wrench (a nice low Nm-rated one for light duty).
Question is what torque to tighten the outer locknut? There's probably a standard for the thread of the pedal spindle but this update is as much as anything an update to say that it was pretty easy to knock-up a tool to do the same job as the £60 Shimano jobbie! It probably cost £6.
I’ve got this tool. Doesn’t fit inside dx pedalsThe Shimano Tool TL-PD63 is designed to adjust two different pedal sizes
The tubular sockets measure outer 11mm / inner 8mm or outer 10mm / inner 7mm
All sizes nominal and measured A/F ( across flats )