Any way to deinterlace incorrectly uprezzed interlaced footage?

[chaynik]

I'm dealing with some 1080i material that has certain archive footage clips badly upconverted from SD. The result is what you get by just taking interlaced video and blowing it up assuming it's frame-based, all field relationships are broken and you get nasty sawtooth artifacts (not the regular combing).. My goal is to remove it and I've tried all kinds of combinations of resizers (nearest neighbor/pointresize as well hoping that it would just discard every other pixel/line and restore the bad upconversion), as well as multiple SeparateFields(), etc. No luck.

Here's a sample clip in huffyuv format:
http://rapidshare.com/files/17500495...laced_pan2.avi

Thanks in advance!