I have two super 8 films from 1978 and 79, where the footage was all processed at the same lab. Camera footage was Kodachrome 40 . I had not viewed the films in about ten years. Upon screening the the footage , which had all been perfectly exposed , now looks about 1 stop underexposed, with the colors obviously, now muted. It is apparent to me the film emulsion is degrading, my guess probably from insufficient stabilization in the original lab processing. I have Kodachrome 8mm films from the mid-60s that still look new. Has anyone experienced this? The film reels were stored in their individual closed plastic containers. I have now drilled holes to allow some air ventilation, although this has not been a problem with any of my films from the 60s. Has anyone encountered this? Any solutions to halt the degradation process? Thank you for any help.