A deal to buy Norman Mailer’s quirky Brooklyn Heights home has fallen through, and the property is no longer on the market. The sale of the unique multilevel, three-bedroom apartment — designed by Mailer himself to resemble the interior of a ship — made headlines when it went up for sale in April with an asking price of $2.5 million. A buyer came forward in August, and a deal went far along enough that Mailer’s offspring, and acolytes, held a farewell dinner there over the summer. They had also begun moving out the legendary author’s belongings. But sources say the buyer has backed out. Film producer Michael Mailer, the author’s son who had been living in the space since last year, confirmed that the home “remains with the Mailer family.” Proceeds from any sale were to be split among Mailer’s nine children. The listing had been with Dolores Grant, a Corcoran Group broker who lives in another apartment in the building. Corcoran has taken the listing off its Web site.