Not sure how much help I can be...  sorry...  but...  there is a
publisher in Paris named Billaudot that publishes a lot of his music;
Dover Publications in Mineola, New York, USA (a very widely-distributed
publisher) just released a score of many works of his for piano including
the solo piano concerto, solo symphony, Festin d'Esope, and some other
pieces (titled "Festin d'Esope and other pieces" I think- I have it
somewhere about and can check though;) Masters Music and some other
publishers have individual publications of his music out as well.  A few
decades ago Raymond Lewenthal (I think!) released a pioneering collection
in score of works by Alkan including the Quasi-Faust movement of the Quatre
Ages sonata, the chant "Fa", some Esquisses, and other works that is
probably not still in print, but one can hope? -Eric Schissel, not certain
about this alas...  sorry I'm not more help with this

Eric Schissel <[log in to unmask]>