Art by Gary Grimshaw, the image is featured in the Art of Rock book on page 297 (plate 3.131).
Thick flat index card stock flyer is in excellent (B+) condition; aside from a couple of ultra-tiny staple holes in the upper right corner, a couple of extra-thin diagonal bends in the lower left/right corners, a tiny bit of ink spread in a couple of areas and a trace of surface wear, it is a SUPERB example of this INCREDIBLY scarce early-'70s Grimshaw item from Ann Arbor.