I have no background in digital or analog circuits, but I am handy with a soldering iron. I have a Philips CDi 210/40, and apparently, it's relatively straightforward to mod these to output NTSC ...

AmpliTech Group’s Division, AGMDC (AmpliTech Group Microwave Design Center), Inks Distribution Deal with Component Distributors Inc (CDI), a Global Value-Added Distributor of Electronic Components ...