Sounds like it should be fixable to me, though you'd almost certainly need to mess with multiple settings in the geometry section of the service menu to get it perfect. I say feel free to have at it after reading up on the service menu stuff first (on this forum and and other sites on the net). Before making any changes, you'll probably want to write down all current geometry settings so you can go back to what you've currently got now. This is important because you
will (at least initially) have a tendency to pay too much attention to one area of the screen and get it perfect in that one spot and not realize that an adjustment you made actually made it quite a bit worse in another spot (i.e., worse than the original defect was

). If you remember to write all original settings down, at least you'll be able to get back to what you originally had, even if you're committing settings as you're going.
You'll also almost certainly decide to spend some time in the dynamic convergence part of the service menus as well once you're satisfied with the geometry - I know that on my set, fixing geometry worsened my convergence in spots until I made adjustments with that as well, though I saw that convergence needed some work before I ever touched the geometry settings anyway.

As an FYI (and maybe someone could help me here), I could not find anything to make any adjustments to vertical convergence at all; perhaps that can only be done with static convergence adjustment? (i.e., cracking open the set and making some physical adjustments, which is definitely beyond what I'm willing to do

).