He was born in Boston.
Here's what I posted in Stump the Bookseller, years ago:
http://www.loganberrybooks.com/solved-d.html
THE DELICIOUS PLUMS OF KING OSCAR THE BAD by Rick Schreiter, NY Harlin Quist (1967). "Geoffrey Hopewell, the story's hero, quietly goes about his business of eating the delicious plums of the king & proving that perseverance truly is the key to success. Magnificent illus in shades of brown, tan peach. Several pictures of Uncle Benjamin traveling in his hot-air balloon, including on the dustjacket cover. A delightful book! Illustrated by Rick Schreiter." I managed to remember the title almost three years ago. As I described it, the king decides to hoard all the plums from a special tree for himself, one boy refuses to accept this, declares he'll ask for some, everyone laughs and says his head will roll, including his enemy Tobias Smudge, and the hero gets taken to the castle by his uncle in a balloon. The humor reminds me of Roald Dahl, somewhat, and even when it doesn't, you know it's post-1960 from scenes like this: "Sometimes he and his friend Kevin would sit on the hill where you could see the castle and Geoffrey would talk about Kings and Plums and Why Things Are the Way They Are." Or: "SUDDENLY, over him fell a huge moist shadow!"
WRITINGS:
*(Juvenile; self-illustrated) The Delicious Plums of King Oscar the Bad , Quist, 1967.
*Also author and illustrator of The Modest Advantures of Barnaby Dob.
Illustrator:
*Richard Arthur Warren Hughes, Gertrude's Child, Harlin Quist, 1966.
*Edgar Allan Poe, The Purloined Letter. The Murders in the Rue Morgue, F. Watts (New York, NY), 1966.
*Eve Merriam, Miss Tibbett's Typewriter, Knopf (New York, NY), 1966.
*Barbara S. Parker, My Street, S.W. Singer Co (Syracuse, NY), 1967.
*Edgar Allan Poe, The Fall of the House of Usher, and Four Other Tales: The Black Cat, Ms. Found in a Bottle, Three Sundays in a Week, The Oval Portrait, F. Watts (New York, NY), 1967.
*Edgar Allan Poe, The Pit and the Pendulum, and Five Other Tales, F. Watts (New York, NY), 1967.
*Robert Louis Stevenson, The Strange Case of Dr. Jekyll and Mr. Hyde, F. Watts (New York, NY), 1967.
*Hans Christian Anderson, Great Claus and Little Claus, Grove, 1968.
*Anderson, What the Good Man Does Is Always Right, Dial, 1968.
*The Derby Ram: A Ballad, Doubleday, 1970.
*Delmar W. Karger, How to Choose a Career, F. Watts (New York), 1978.*
*Jay Williams, The Practical Princess, and Other Liberating Fairy Tales, Parent's Magazine Press (New York, NY), 1978.
Lenona.