I would add that an old, faded color print is a very bad source for a video transfer. Surely a decent IP or a negative is available somewhere. What I’ve seen in the past with Imagica scanners is that they tend to clip with sense material, particularly prints. They’re fine with camera negative or inter negative. My personal preference is Si the Northlight scanners, which I think deliver a better picture overall. The DFT scanners are also good provided you get he pin-reg option (which will be dodgy with very old material).
If the yellow and cyan layers have faded, the problem with the magenta that remains is that it’s going to have a lot of color & density “breathing” issues. Even if you can create or duplicate the bad color layers, it’s going to be unstable unless you have very sophisticated processing available.
I have seen cases where a missing color record from a 3-strip nitrate project was missing or very badly damaged, and they were able to reconstruct it enough that the resultant color was acceptable. But we’re talking pixel-by-pixel mapping over a period of months and months… not simple and not cheap.