Must be a Videocolor monitor then. With the KT-3, I've never seen the monitor schematics (I only have the TV chassis service manual - everything is the same except the RGB input & sync boards). If you can figure out a TV that it might have been in you may be able to dig up the service manual for it.
Keep & restore of course

Use plain glass for the bezel until you can find a Scramble glass

Paul.