Cheers Paul...The idea of recalibrating your arm made me smile, but you are right of course, we all do it all the time on the less important stuff!!

Be interesting to know how far out you are by running a test on a std 12mm somewhere else on the bike...maybe we all should, the closest one gets the job when any of us need to rebuild!

It's difficult enough getting a spanner in there in the first place, be interesting to see if I can get a crows foot in, level and torqued...bleeding knuckles coming up!