Tir Nan Og (2004) page 82: Titou's Workshop

French fantasy artist Georges Reynolds released a book collecting his fairy/troll-themed pieces, most of which were paintings. "Tir Nan Og" gets its name from the Irish name ("Land of Youth") for the realm of Faerie. This sheet with two sketches sits found among "Titou's Workshop," a collection of pencil drawings at the rear of the book. "Titou" is a French diminutive of "Antoine" equivalent to English "Tony."

I acquired it on Heritage Auction without any information except the date and author's name, but with a little help was able to sleuth out its origin, so now we all know.