If you like early-1940s Nat, you might want to check out the MacGregor transcriptions as well. I used to have the old Laserlight box that collected many of them, and then traded up for the Music and Arts set. The trio backs singers on a number of these tracks as well--Anita Boyer, Ida James, and (one session only, I think) Anita O'Day--if you want the trio only, you might want to go with the Laserlight, which leaves off most of the backing numbers.