The power of service level convergence has led me to fiddle, enjoy, fiddle a bit more and then get to the point where I think the settings are well mesed up

... covergence is lovely, geometry is woefull.
The scrolling info bar on Sky Sports News now makes me sea sick
On my last set, I did most of the geometry correction in the service menu .. service level convergence allows this to be much more visibly done using 'green gun' alignment.
I suspect the best way to get this right is to have some sort of overlay on the screen with dead staright lines at the correct spacings ... has anyone done this?
What are the correct horizonatl and vertical spacings for the convergence grid on the Toshiba 42PW23p?
Mark M