Shakespeare Reference in The Lime Pit

Jonathan Valin's novel The Lime Pit contains a reference to The Tempest. That reference comes on the very first page. Valin writes, "He was an interesting character, Mull - a kind of corn-belt Prospero who had tricked two realtors into parting with a large sum of cash" (p. 7). 

The Lime Pit was published in 1980. My copy was from the first Avon printing, May 1981.