Now that I'm not in a rush, I went back to correct the slight over-brightness, which didn't look so bad in the live action, but did show it's deficiency in the cartoon.
When working the live action shot, I used mostly the girl's hair and face for the color correction. This time I reduced the bright areas of her face (the 35mm target was a different shot) for a now subtly better correction (the background opened up a bit, too):
first correction
low gamma high midtone
RED 0 1.5 255 -5
GREEN 0 1.4 255 -5
BLUE 0 1.2 255 -5
correction tweaked
low gamma high midtone
RED 0 1.4 255 0
GREEN 0 1.3 255 0
BLUE 0 1.1 255 0
LUT capture 35mm-guided color correction tweak
And, when blindly applied to the cartoon, it now looks less washed out:
This demonstrates that maybe a single correction can be used as a general correction across a single reel and, perhaps, multiple reels.