Now that makes it a piece of interest to me, as I have only a not-so-great sounding Affinity LP reissue of the Decca sides, apart from excerpts on the big red Capitol box set "A Musiacl Autobiography", which also featured two discs of transcriptions etc.
The Dexter session, btw, left me cold. Not for Nat, but for Dexter, who sounds too immature to me. Since I had the Affinity LP and all the Pres stuff I skipped the Riffin' box.