How good is your pareidolia?

[oshfdk]

Hypothetically, the original writer looked at yesterday's dry pages and added a few improvements. Yes, there are ink variations, certainly there can be retouches and corrections, but what is the chronological evidence to show a timespan of months, years or centuries?

I assume if "the retoucher" produced "invalid" glyphs, this would imply that "the correct" stokes faded out completely, which takes quite some time, I think. I don't think these are invalid glyphs, just relatively rare variants.