Yeah, now I see what you're talking about, it could've been introduced when imagehack converted the image to JPG, but most of it is more likely video noise, I'm no expert in the field, but I guess it could be many things, player, cables and how it was captured etc. I see no big problem with it, in fact this is some of the finest LD-captures I've ever seen. Did you guys see the same noise on the samples I posted? Cannot check this myself at the moment.
Your suggestion on applying a layer of this noise on the DVD-footage sounds strangely familiar with what Moth3r suggested to me a while back regarding the alien subs in SW, it sounds like a very good idea, I just have to find out exactly how you do that. ;)