After doing some more digging, its clearly labeled electrohome on the board, and it clearly has the BNC connector for video, but it doesn't match any of the NTSC board pics I've seen. I went ahead and pulled a datasheet for U1, and its a typical color TV NTSC decoding IC, so I'm confident the intention of this board is NTSC, but where it's originally from, I have no idea, and where to find documentation is even more troubling.