Thanks to all on BOB and CR
Dear all,
A big thank you to everyone who considered my problem, I've finally got the darned lock open. I filed off the tab that guides the key into the cyclinder, several people having suggested this method to me. That method did away with the last resort approach, cutting through the lock. I can still use the lock now, but this incident has given me second thoughts about taking the lock with me when I do the 'Raid Pyreneen' in France at the beginning of next month. Since these locks do seem a little more vulnerable than I had once imagined, the weight penalty they incur seems too high to justify carrying one into S.France for added security. I would prefer to just take my deterrent cable lock.
Yours, thanks again,
Mark, Stockton on Tees, United Kingdom