Regarding a video preamp, I just updated my CTC-4 article with a new section at the end, describing what I built:
https://antiqueradio.org/RCACTC-4ColorTelevision.htm
My preamp didn't work, due in part to a wiring mistake. I fixed that and messed around a little more, and then pushed the whole thing aside because I was burned out on the project.
Anyhow, I have to believe that the basic design, taken from the 1956 article in
RCA Broadcast News, will work if someone takes the time to build it correctly.
Phil Nelson
Phil's Old Radios
https://antiqueradio.org/index.html