Igniting a project that has been in development for several years, “Con Air” scripter Scott Rosenberg has been brought on to pen a full rewrite of Universal Pictures and Imagine Entertainment’s Matthew McConaughey vehicle, “Johnny Diamond.”Imagine’s Brian Grazer will produce the pic along with McConaughey and Todd Gustawes, his partner in the j.k. livin’ production banner. Adding even more star power, Academy Award-winning screenwriter William Goldman has been brought on to oversee Rosenberg’s rewrite of a project based on an original idea by Imagine co-chairman Ron Howard, who sources say may also direct. Originally titled “Hep,” the film has been described as a stylish period piece a la “Chinatown” that looks at Los Angeles in the early 1960s. The story centers on a slick private investigator who must scramble to solve the murder of his partner. Imagine’s Jim Whitaker oversees the project for the company. Imagine has had the film in development for more than four years. Rockne O’Bannon was hired to do the original screenplay, and John Byrum later was brought in to pen a rewrite. McConaughey, who recently wrapped Richard Linklater’s “The Newton Boys” for 20th Century Fox, has emerged as a young A-list feature star, earning his lunch with roles in such pics as “Dazed and Confused,” “A Time to Kill” and most recently “Contact.” He was mentioned in talks with Universal and Imagine to produce and star in “Johnny Diamond” in December (Daily Variety, Dec. 16, 1996). In 1995, McConaughey and Gustawes formed the j.k. livin’ (“just keep livin’ “) banner, which has a first-look production deal at Warner Bros. Rosenberg’s screenwriting credits include “Beautiful Girls,” “Things to Do in Denver When You’re Dead,” “Disturbing Behavior” and “Bad Moon Rising.” McConaughey is repped by CAA’s Josh Lieberman and Kevin Huvane. Rosenberg is repped by ICM’s Barbara Dreyfus.