Hope this helps someone else
Had a Galaxian with an old Wells Gardner k4500 monitor (original for the game). To install a k4900, I had to re-wire the monitor connector since there wasn't one of those small adapter PCB. Below is the original mapping and change needed to connect to a k4900 (or any other standard res monitor).

Had a Galaxian with an old Wells Gardner k4500 monitor (original for the game). To install a k4900, I had to re-wire the monitor connector since there wasn't one of those small adapter PCB. Below is the original mapping and change needed to connect to a k4900 (or any other standard res monitor).

