Ya' can't get much more seventies than this:)
Restoring a faded and color-cast image like this is normally fairly easy...especially if turned monochrome.
But in this case there was a honeycomb pattern in the original print (shown in an enlarged insert).
Descreening and various blurs proved ineffective at various scan densities and eventually I retained enough detail to actually clone pattern cell to pattern cell. Anything less would show in print as an anomaly.
(Edit 081521) I just tried the standalone portion of V5.0 Focus Magic and the 'Despeckle filter' works very well on this image. As a bonus the smallest imperfections disappeared as well as the repeating pattern.