Tom,
Firstly, thanks very much for the concise and detailed reply.
OK, RF it is, at least at first. I do have a 'scope but no sweep/marker. So let's hope that replacing the caps and checking the resistors will get it done for the IF. If not, I wonder if I can find someone I could just send the IF to.
As to video source, all I have is a laptop with VGA and HDMI. I live off the grid and so I just use a laptop as my PC. Although I do have enough power to run whatever I want now, the laptop is a legacy from when I first moved out onto the property and had little power storage.
So, looks like I need something like this:
https://www.amazon.com/ViewHD-Compos.../dp/B00LK95VNQ
and run that into something like this:
http://www.ebay.com/itm/Blonder-Tong...-/272304780489
I'll start cruising the thrift stores when I'm in town and pick up a small CRT TV set.
Thanks again for the help!
JOnathan