Windscreen wiper wheelbox wrench

["Jerry K" <jkprod@hc.cns.net>]

Help  !!!

I am in the process of striping down my second B for total rebuild and have
again run into the problem of getting the eight sided nuts off from the
wiper wheelbox.
Does anyone know of (and where to get) a ~3/4 eight sided (not eight point)
wrench to fit this little nut?  I either tend to strip the corners or split
the nut when I use a standard open end wrench.  What's the trick?

Jerry K
3  74-1/2 MGB
1  75 Anniversary MGB