Yes, the color of the later scarlet printings is indeed the first and biggest tip-off.
The print quantity of J76 also makes is far less likely.
Lastly, from your own image, when the top and sides are compared by aligning the perfs at the bottom, they are "off" by about a 1/2 at the top, which is close to 20mm, indicating a compound perforation, which must be from the J86 family.
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