My two cents. I think the 1999 color timing is certainly revisionist, honestly; however, it's a damn good look. In other words, it's aesthetically pleasing to me. The new one looks like a fairly accurate representation of the negative.

The true mono, though, is definitely worth preserving.

I've said this before for Alien, but a good color reference to see how prints looked would be the Horror Documentary "Terror in the Aisles." It's scanned in HD at the Halloween II Universal BD. It features a bunch of clips from horror and action movies that likely were taken from 35mm prints. As I recall, it has loads of Halloween clips.