1964 Heathkit B&W had DC restorer
 

2 diodes - one for video detector, one for DC restoration

I remember the 12" Heathkit B&W TV I built about 1979 did not have DC restoration. That was about when I was first learning TV repair and circuits, and I wanted to add that feature but never did try. That set did have a lighted channel dial and memory VHF fine tuning though, features rare or unique on a small B&W in the late 70's.