What's new
I'm honestly not sure. I think it moved a bit, but not much lower. I'll try the new cap I just posted and see.

Also, I've never seen the "curl" before on any CRT I've owned....every other CRT just over/underscans like the other two sides. There's no way to adjust that?
The "Curl" is fairly common in arcade chassis...BUT some will over scan better than others... It depends how they are designed to work with it.... Its also more common with the width.. and not the height of the picture on the screen.
The JAMMA H/V board @'mmmonkey suggested just came in. It works, which means the new V cap should be a solid fix...but as expected, the curl is still there. So, that board turned out to be an excellent tool and I'm glad I got it...but I'm also glad we took the time to work on the cap fix!:

The new caps should arrive on Friday and I'll test those as well. I know everyone is probably about to tell me to leave well enough alone...but how can I try to fix the curl?
So, the new caps came in last night. I put the whole thing back the way it was, except I swapped C438 with this: https://www.digikey.com/product-det...nic-components/ECW-HA3C223J/P15425-ND/3088422

...and there was no picture on the screen. I put the original cap back into C438 and everything worked again. Was that not the cap that solved the vertical centering issue?

The expansion board seems to work fine, but the "curl" is really annoying. I might try to adjust the yoke and see if I can fix it there.