In concurrence, and my two bits - yes ,it is a booklet I have seen in Boulder, Colorado gift shops, by Susan Politz Shultz, who writes many greeting card tag lines for Leanin' Tree - Western or Native American themes. She has written many books of poetry primarily, and short "feel-good"/better phraseology, very much loved and popular author around these parts.
The Pony Book Man shows on the cover a Centaur - a Bearded, Long-haired man's torso and head,arms, and a small horses body for the tail, 'extended trunk' and back of the torso, and all 4 legs in hooves. The humans upper torso man wears a hat and smokes a pipe as I recall. Its very nice and tasteful.
Blue Mountain Arts, and/or Leanin' Tree Web-sites should also have it, as she writes for both. I understand loosely that Gordon partially wrote it, with I believe an extended poem about the Pony Man, from the song basis. She made it into a smal booklet. She has incoporated Lightfoot verse into many of her poem and phrase booklets in general. Untapped Lightfoot collector area, I think. I wish I'd bought 'em up when I saw em. I worked across the street from at least Leanin Tree's location in the 80's. Hope this helps, and is not redundant.
I wonder now if the extended poem about Don Quixote on the back of the album LP cover art, which talks more of Cervantes, the author, and roughly 3 x the verse, went on to Shultz, as did the Pony Man. ??
Meaning of the song Pony Man
Amazon.com: The Pony Man: Gordon Lightfoot,... 
