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?
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...
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.