Thanks for answering!
First, it’s 640 X 480 because it was shot standard (720 X 480) and then because of advice I got from this forum I changed it and also to square pixels. Over time these clips were modified using After Effects (and rendered out in Animation) and using Studio Artist (which was also Animation).
It’s the Studio Artist that makes the effect you mentioned. I did that because I’m also using animated material and it looks better with that than stark reality. It’s a step away from real — which I wanted. So the footage has been trashed to some extent. I can’t go back to the original footage.
I’ve done a deeper de-interlace with Natress and that helps the squiggles & pixelation somewhat. I would love to find a cure, but maybe there is none, because the footage is so various and strange. I CAN’T go back to the original un-modified footage. There’s too much and it’s in too many places.
You can see what I’m talking about at
https://straightlife.info/movielinks.html Some of it looks pretty good. It’s been turned into flash (by somebody else) from mostly Animation 720 X 480 codec.