Three on A Couch is a Columbia picture. Paramount still has the excellent Whose Minding the Store?, It's Only Money, Don't Give Up the Ship and the last unreleased Martin/Lewis film Three Ring Circus.
As for getting them on dvd, it probably is a lost cause. Paramount is out of the business of releasing classic movie titles. Anyone that can get these released is a miracle worker.
Paramount did outsource MONEY FROM HOME to Legend Films so there is still a chance. Add to the Lewis-Paramount films: ROCKABYE BABY, the Jerry Lewis "version" of Preston Sturges' THE MIRACLE OF MORGAN'S CREEK!
Rock-A-Bye Baby IS available, along with The Geisha Boy,in Region 2 .......both anamorphic widescreen too. I have no idea why they aren't available in Region 1. I'd also love to see It's Only Money, and Who's Minding the Store? These all are classic Lewis/Tashlin!