Desilu was definitely on a downhill slide when Desi Arnaz sold his half to his ex-wife. During the previous decade, the company had several network series beyond I Love Lucy; these included December Bride, The Ann Sothern Show, The Texan, Those Whiting Girls and the venerable Desilu Playhouse, which gave birth to The Untouchables and The Twilight Zone.
By 1964, Desilu was down to The Lucy Show. Sure, they were renting facilities to Danny Thomas - Sheldon Leonard, producers of Make Room for Daddy, The Andy Griffith Show and The Dick Van Dyke Show... but Lucy certainly didn't own any piece of those hits. Hence the "all-out effort" described above.
Which led to... well, as far as Martin Jurow's contribution, if any, it's lost to time. Jurow's IMDb entry lists only further motion pictures for Blake Edwards during this period: The Pink Panther and The Great Race. Goodman and Klein came up with something called Good Old Days, a family sitcom set during the stone age. A live action Flintstones rip-off, perhaps? The star was Darryl Hickman (as "Rok"); the parents were played by Kathleen Freeman and Ned Glass. The show didn't sell, and the pilot aired on NBC in July 1966, in the days when networks "burned off" their excess waste during the summer months. (Come to think of it, aren't they still doing that?)
Which leaves us with Gene Roddenberry... and we all know what he created for Desilu, don't we?