Just wanted to chime in. I sell modded Intellivision, Atari 5200, and Atari 7800 consoles on ebay (userid: glennfre). I make my own boards for the Intellivision's consoles and can provide composite A/V mod service, consoles or boards to anyone in need.
I have attached 2 photos, a modded Intellivision board, and the homemade boards I make. I have not found a need to use printed boards for this simple setup (2 transistor,3 capacitor and 8 resistor circuit).
I use quality parts from digikey so just message me if you want your system modded, want to purchase a already modded console, or just want the mod board.
I have sold consoles to atariage forum members in the past so maybe they and vouch for me or you can check my ebay feedback.
Thanks,
Glenn