I liked the sample, these old video transfers have an aesthetic appeal that's hard to describe.

I would definitely increase the white level (contrast), then perhaps you might want to carry out a gamma adjustment to darken the lower end of the luma curve.

So I take it the sample video is from a multi-capture median script, while the screenshots above are from the raw captures?

Yes the script above is simple to modify for five captures. There is a noticeable improvement when going from a 3-cap to a 5-cap average, but I've found that five is the sweetspot; more than this and the additional time and storage required outweigh the benefits of a small increase in quality.

Regarding the temporal soften command, I don't think the scenechange parameter (the 4th figure) is required, and I cannot tell any difference between modes 1 and 2 (the 5th figure). Obviously you would use radius=2 for a 5-cap average.