I zoomed in as far as I could go and saw some occasional flecks of red. Is that just lint, or remnants of when it was defaced in the 70s?

There is an "Artwork Details" feature and in it a section "Paint residues from the act of vandalism", they are remnants of the act. I quote:

> The varnish applied in 1962 served as a layer to protect the polychrome and the red paint could be removed without damaging the original.

> At the present time, macrophotographs show reddish micro-residues, almost imperceptible to the naked eye. In some cases, this has entered the fissures.

I lack an answer, but for other interested, here is a link with more details regarding the event:

https://en.wikipedia.org/wiki/Tony_Shafrazi#Shafrazi_and_Gue...