OK, as a baseline I get about 1.5 volts of average DC variation at the output of the detector diode, from bright to dark scenes. When I say average, I mean that's what my scope is telling me when I look at the composite signal at the detector output. Then at the cathode of the CRT, without the restoration circuit, I see about 10V DC in variation, but that appears to be faster transients. With the restoration circuit in place I only see about 5V DC change. My first thought was that that small variation can't be very useful restoration, but then I don't know what would be considered acceptable. This was while watching my first season Gilligan's Island DVD. Right now I'm having a hard time convincing myself it's beneficial. I need to spend some more time with this as it's much harder to analyze with the scope than I anticipated. It's possible I'm one of those individuals that's not sensitive to background level.