Thanks Anon,
Unfortunately (or fortunately) I was aware of this arrangment. I tend to think that because I bought some rather cheap wrenches so they would be :
1. Thinner therefore easier to bend
2. Thinner and easier to fit on the locknut
Which is causing me some problems because I do not believe that the jaws of the wrenches are precision cut so I get some play when trying to hold the acorn nut.
I'm gonna have a cup of joe and then go at it here again in a few minutes and see how things go.
I had this nasty dream last night that I was turning the locknut the wrong way...! Pretty darned frightening.