Atari 720 to Major Havoc

For those of you who have been following my project, I have finally finished the technical
portion. My Major Havoc now lives in full color (converged pretty good too) in a 25" 720
cabinet complete with custom control panel. There is an awful log of bowing on the display, so
it is probably worth my while to install one of Clay's display correctors (Clay: any chance you
want to donate one to a good cause?)

I do have one question. During the convergence, even though it all went smoothly, it is still
a little off at the top and bottom of the screen. The red and blue are both dead on with each
other, but the green gradually pulls away the further away from the center you get. The
convergence magnets don't seem to fix it, and the yoke appears to be at its optimal location,
yet I still seem to have this problem.

Is this why magnetic shunts are sometimes used? Could it be the location of the magnetic
convergence assembly itself? Or is this just the effect of a yoke not designed for a
particular tube? As it is, it does look pretty good already. I guess I'd just like to make it
perfect. I'll post a picture later tonight showing the effect that I'm seeing.

Jon