They were broadcasts that Ellington did for the Treasury Department in 1945 (continuing into 1946, I think) encouraging people to buy war bonds (later re-titled "Victory Bonds" after Japan surrendered. There are a number of tunes that Ellington rarely performed after 1945 (such as "Blutopia"), some pop songs of the day, and a fair amount of Ducal songbook staples. Lots of performances of The Black, Brown and Beige Suite... and peppered with Duke pitching for war bonds. Many of the shows were done on the road (I'm particularly taken with V. 6, which contains a broadcast from Evansville, Indiana). The liner notes are generally pretty good, done by several longtime Duke connoisseurs. You can find them online for $20-$21 (including shipping) or order them directly from Storyville.
Thank you for the information David. I've just ordered vol. 1 in order to get an impression.