A great deal of desireable films from the Palomar library are MIA. The Stepford Wives..The Heartbreak Kid....Law and Disorder and yes Sleuth all deserve Blu ray upgrades.
I stand to be corrected but I believe it has been established that the rights to Sleuth (as well as The Heartbreak Kid and The Stepford Wives) are held by Bristol-Myers Squibb, a pharmaceutical company (sic). When Anchor Bay released those titles on DVD in the late 90s, they had to license those titles from Bristol-Myers Squibb and the copyright on the DVD says "1972 Bristol Myers Squibb". Of course, in the ensuing years, it's possible that Bristol Myers sold their rights to another party. Whether they only have the U.S. rights or world rights, I don't know.
I believe rights to The Stepford Wives are now with Paramount, as they obtained the rights when they produced their 2004 remake and subsequently issued a DVD, which os now out of print. Most Palomar films are now held by Disney, as Palomar was an ABC division handling production of theatrical films. Whether or not Bristol-Myers Squibb continues to hold any residual rights remains to be seen, as all three of these films have been remade during the 2000s: Heartbreak Kid and Stepford by Paramount, and Sleuth by Sony.
Further "Sleuth"ing has determined that Bristol-Myers provided seed funding for Palomar Pictures, so all rights should be with Disney now.