Olive's Paramount deal does not include any films produced by CBS (THE CHALLENGE, DARKER THAN AMBER). CBS owns them and decides whether or not to put them out through Paramount's home video label. Seeing Paramount's almost-complete abandonment of catalog titles, it is most unlikely we will see them surface anytime soon.
REINCARNATION OF PETER PROUD should be fully absorbed into Paramount now by their purchase of Cox Broadcasting, but the rights to WILLARD and BEN are shared 50/50 by Paramount with the legal consortium that controls the Cinerama library. It is why Scorpion, who made a deal for many Cinerama titles, could not get those prime two. Some rumors floated that a sublicensing deal was close to happening, but those proved to be just rumors.
I believe WILLARD and BEN, being Bing Crosby Productions titles, have reverted to his estate.