early 60s Zenith, turns on, poor picture

[photon1138]

Hi, I just got this Zenith TV which appears to be from the early 60s:

http://afinch.com/client/tv/tv.png

I don't see any identifying marks except "16G27" written inside the case. It turns on, I am feeding it a signal from my blu-ray player through a radioshack RF modulator, I have played with all the available settings (fringe lock, vert size, vert lin, AGC, horiz lock, vert lock, contrast, brightness) and this seems to be the best picture I can get out of it:

http://afinch.com/client/tv/screen.png

here is roughly what the signal should be (sony blu-ray menu):
http://afinch.com/client/tv/signal.png

I would like to know what the problem is and how I can fix it. I am attempting to use it as a prop in a movie. Thanks!