That is a sweet System 3.

I also have a '79 System 3 19", the one with the single knob varactor diode tuning. Mint, not a scratch on it or a spec of dust inside it. It was in the recycling place with the power cord cut. Works like brand new still, and excellent picture.

http://i1164.photobucket.com/albums/...-09-06_229.jpg