FWIW, I've picked up some of the Topps reflection photos, which are positives on which the Topps artists inked highlights for cards. They too are showing signs of degeneration due to unstable dyes. Here is an example from the 1975-76 basketball issue:
Bob McAdoo:
Those Buffalo unis used to be nearly the same color as the highlights and the background has lost a lot of color.
Based on what I've seen I think my future vault purchases are going to be limited to cards, uncut materials and contracts. No more photographic materials.