Thanks everyone, I really appreciate your contributions! So now I'm not so bothered by the card going missing, since it is apparently just a very damaged card and not a fairly uncommon print variation. That makes the whole issue more of a curiosity than a real problem.
I think your explanation of chemicals/fade is logical with my example, as there are parts that have the correct burgundy color indicating that ink was present during the printing process. I have seen other Willis portraits with completely gray backgrounds. One was on ebay last year. And I've seen what I thought were "violet" variations.
Is your opinion these things are all due to chemical reactions or fade, as opposed to missing colors in the print process? Here is an example:
https://www.ebay.com/itm/144161666607