Interlaced MP4s flagged as progressive

[Mr Chris]

I'm trying to rescue some badly-processed MP4s the best I can - please see the attached sample clip.

These videos are flagged as progressive, but they're clearly interlaced. Under normal circumstances, playing them back and forcing deinterlacing on the fly wouldn't be a problem, but here we have the double-whammy of VLC (and everything else) getting the field order wrong. I've tried to find some sort of flag that I can switch, and to repackage them into an MKV file that's correctly marked as TFF interlaced, but nothing's worked so far.

What are my options, if any, other than re-encoding the lot?

[davexnet]

Sorry to bring bad news, but:
There are a few older threads where it was not deemed possible
https://forum.videohelp.com/threads/377932-Is-it-possible-to-change-Scan-Type-flag-on-MP4-file

Secondly, the progressive encoding with chroma sub-sampling of 4:2:0 has harmed the chroma, the two fields get blurred together.
https://forum.videohelp.com/threads/398436-In-VirtualDub-where-is-the-capture-BITRATE-...ng#post2592253