Perfect Patina, Earlyish 20th C. Graphite Drawing on Toned Paper, Yielding Very Excellent Moon Face

I have to say I'm pretty obsessed with this drawing, to my eye made a hundred times better by what seems to be a chance stain/toning, which turned the graphite drawing of the features of a face it into a face on the moon. Perhaps I'm wrong and the drawing was made after the discoloration, but I really don't think so. Just so right, including for this punched edge on a second piece of paper to which it was attached, and a penmanship practice exercise on reverse. Love. 10" x 8" overall, perfectly aged and worn, earlyish 20th c.