One other thing I forgot to mention, look at the placement of the 50c...
On the lighter chip the "0" is on the right side of the white 'V' in the Kings Clothes, while on the darker chip, the left side of the "0" is below the white 'V' in the Kings clothes...

Also when I scanned these chips, I used the same Brightness and Contrast settings... So the scanner didn’t add any "bias" to the resultant images...

Regards,

Dick