One of the Producers Was Jerry Bruckheimer
Though there were two producers listed on "Farewell My Lovely." who would move on to do another Marlowe film with Robert Mitchum a few years later -- The Big Sleep in 1978 - I was surprised to read of Jerry Bruckheimer as the third.
So there Jerry is, before becoming half of the blockbuster 80s pairing of "Simpson/Bruckheimer" films (Top Gun, Beverly Hills Cop, Days of Thunder) and way before going solo with PIrates of the Caribbean" after Simpson died.
Though Farewell My Lovely is a gritty, rather low budget seventies-type film, I suppose you can see Bruckheimer's youth and taste here --- the violence is a little more violent, the sexual touches(Hookers, a whorehouse) keeping things a bit sleazy yet sexy.
Maybe that's why Jerry signed on for this one. Would have Don Simpson approved?