@nrm3333, yes, that is going overboard. Unless you just want to throw money at it.
First...all batteries leak, even Lithium batteries. You should get those off the board and install NVRAM. With WhiteStar MPUs, the job is trivial.

The usuals issue I find with comms between the MPU and the Dot Controller, in order of probability, are...
1. Flakey ribbon cable. You can remove the ribbon, and swap the ends to the opposite board as a test.
2. Alkaline corrosion on the dual row header on the MPU that is labeled "Plasma Display"
3. Failed 74LS374 on the MPU board that acts as an output buffer to the dot controller.
4. Failure on the dot controller.

I'm happy to help with repair of either/both boards, install of NVRAM, etc., assuming the issue can be isolated to a board.

Regards
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info

The resolution to this particular problem was to socket and replace the 74HCT273 that acts as an output buffer to the plasma display. With the proper tools, technique, and experience, the task is straightforward. However, desoldering ICs on WhiteStar boards isn't trivial as ALL of the chip leads are bent over during manufacture.

--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact fore repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info