After researching this a bit it looks like Data East had a factory modification to make a version 1 board work in games needing version 2. Attached is an image of the mod, appears it allows version 1 boards to use the increased ram.

Has anyone ever documented this mod?

I have a laser war board I need to use in my secret service game.

215610-i.jpg

The picture is not of my board, just one I found to use as a reference.

Anybody with a factory modified board able to mark where the jumpers go to and from? Appears the only change was the ram chip size.