I agree, "For Duke" is on my short list for demo discs, along with "Fatha" another fantastic M&K D2D recording. If I put together my short-list of demo records, it would contain:
TBM-Yamamoto Trio-Midnight Sugar (1st pressing)
???-Clark Terry-Alternate Blues (Analogue Productions or some other company reissue)
East Wind-Great Jazz Trio-Direct from L.A.
Concord Jazz-LA4-Just Friends
Analogue Productions?-Doug MacLeod-Bring it on Home
King Records-Mozart Clarinet and Horn Concerto-Gervase de Peyer, Barry Tuckwell, Peter Maag (Japanese reissue of a Decca original)
Columbia-Duke Ellington-Blues in Orbit (1959 stereo recording-proof
that the state of the art in recording has not advanced much in 60 years).
Clarity Recordings-Claudia Gomes-Salamandra
Audioquest-Tuxedo Cowboys-Woman of the Heart