After looking up a Venus 46 on yachtworld.com I admit that that boat bears no resemblance to Muilenburg's boat that he built and described in the book. However, the boat's name was
Breath. I no longer have the book to check the details myself, but here's some content from a website on
Breath and Muilenburg.
"His inspiration came from the design of the boat of a Venus designed ketch. 'These boat standards were very high and shipyards would have cost too much. It was the only way we could get it.' Dorothy said. One influence was the ship named
The Moon. It was built and owned by John and Gillene Frith of Bermuda. They sailed her for years with their three children. Also another inspiration, the designer, Paul Johnson, built and sailed Venus Ketches of several sizes. In the mid 1960′s, Paul created quite a ruckus in Bermuda and everywhere he went with his small ship. Dorothy says, 'The Venus Ketches are inspired by Colin Archers, a Norwegian double ended rescue boat.'"
http://southjerseyexplorer.com/category/the-story-of-the-sailing-ship-breath-st-john/