Speaking of procedural record-keeping, I've duplicated my above color correction steps into a single RGB Curves adjustment -- using the previously demonstrated one-to-one color-compare between the starting capture and the previous correction to get me started. While at it, I tried reducing some of the green cast (but preserving the mint green in the shirt-spectrum-area) while maintaining the stronger colors and higher contrast of the 35mm.

BTW, starting with the cel instead of the 35mm probably didn't make much difference. But it was the cel's initial correction that began with better looking skin-tones (such as it was).

Anyway, let me know of problems using these numbers and, or course, how it looks across the entire reel/film (posting some before-after picture pair examples would be cool). If you can take it from here ... great! If you need closer tweaking, work up something in both cartoon and live-action (per reel?) to demonstrate where it might need to go. The same settings, with proportional adjustments, probably could compensate for different degrees of fading in different reels.

CURVES -- points (in,out)
RGB (0,0) (255,255) = no adjustment
RED (0,0) (88,76) (110,97) (144,166) (202,197) (231,236) (255,255)
GREEN (0,0) (57,60) (115,93) (172,143) (201,188) (220,228) (255,255)
BLUE (0,0) (64,58) (106,76) (181,120) (213,169) (238,237) (255,255)

If your Master::Curves for each R-G-B channel has minimum=0 and maximum=1.0, divide each of the above numbers by 255, for your use.