It all started as a simple job to fix the chainline, which involved turning the Surly sprocket round. However, to remove a sprocket on a SA threaded driver, the driver has to come out of the hub after removing the RH cone. 2 minutes later and the driver is straddling a metal bar in the Workmate, with me heaving on a chainwhip. It comes off, so that's good.
However, the axle is free to move a lot when the RH cone is out...and the planet pinions managed to lose their timing, meaning the hub wouldn't turn freely. Arse. So I stripped the whole thing down, taking the opportunity to change the axle key for a threaded one so I can use a £2 one-piece indicator (available new) rather than a £15 two-piece indicator (not made since the 1960s).
Anyway, it's all back in and running beautifully - the chainline is bang on now - but the 40 mile "bedding in" ride before the Dun Run is going to have to be repeated this week.