Graphical Glitches on Rev 3, MV4 slot board/cab

I have an issue whereupon I am getting a vertical "stripe" of sprite glitching on the right hand side of my screen. The glitching only appears to be on one (?) sprite layer, in that it's not always present, but is consistently present for certain sprites, in a certain location. It almost looks like dead pixels on an LCD, in that the glitch just leaves behind black (sometimes white) squares of empty sadness where it occurs. I have included four pics of the symptom. It's most visible on MOTW.

• I've replaced the PSU already, so at least it's not the PSU itself that is the cause.
• The monitor had a cap kit applied a number of years ago, and the cab has been indoors, comfy, and not run but for maybe an hour or two at a go for better than a decade.

Any other ideas?

• Might it be an issue with the two boards of the MV4 not being seated well?
• Can battery leakage cause this? (I'm in the process of getting parts to install a coin batt, but don't know if the original has leaked as yet)

Here's the link to the album. Any input is appreciated.

: Cartman voice :
"Screw you guys. Ah'm goin' home!"

But, seriously, not screw you guys. Is this like a total and complete mystery to everyone, or am I not providing information that would be helpful in determining the issue?

Are there any other data points I can provide of which I haven't thought?

Is it contained to just one slot or does it occur in all slots? I had a similar thing with certain games in a six slot years ago but it was limited to one slot and it was something to do with the switching logic associated with that slot.

It's all slots.