So nobody ever got a RGB mod done to their CRT TVs, eh ? I vaguely heard about this ages ago, but back when TV/VCR repair folks could still make a living before they went the way of most arcades, extinct.
The idea is you'd install a custom switch and four 75 Ohm prepped jacks for C-Sync, Red, Green, and Blue, and so when the switch is in the RGB-in position, it disconnects the SRGB lines from the TV tuner/output module and reroutes them to the jacks. That's the basic idea for the mod and it was apparently offered by some professionals if you'd bring your TV in. I would bet 'thesteve' knows how to do this. Now how complicated this really is, would you need a circuit for more processing in-between, I dunno, but I heard it could be done if you wanted the option to a regular CRT TV that didn't provide RGB inputs. It's a bypass mod, basically.