Barry,
   Could it actually be the M4, and not the already released M1?
Pentatone Classics has this on their site: 
http://www.pentatonemusic.com/pagsalg/linker5.html#NEW       Vonk Legacy
(Normal cd)    Mozart / Beethoven
   Symphony No.40 in G minor, K.550
   Symphony in A major, Op.92
   Saint Louis Symphony Orchestra
   Hans Vonk
NEW    Vonk Legacy
(Normal cd)    Mahler
   Symphony No.4 in G major
   Saint Louis Symphony Orchestra
   Hans Vonk
NEW    Vonk Legacy
(Normal cd)    Fauré / Schoenberg
   Suite from Pelléas et Mélisande, Op.80
   Pelléas und Mélisande, Op.5
   Saint Louis Symphony Orchestra
   Hans Vonk
NEW    Vonk Legacy
(Normal cd)    Tchaikovsky
   Romeo and Juliet - Symphony No.4 in F minor, Op.36
   Saint Louis Symphony Orchestra
   Hans Vonk 
I'm not too psyched about the other releases, but I will get the Fourth. It was Vonk's last concert as music director. At the time, it seemed like it was a great concert. We'll see if that holds up.