Harry, this appears to be the same anonymous version as on the Delphi Classics edition.
ADDED:
There is an edition from Modern Library Classics, translated by Jordon Stump, that give proper attribution (but through quotes only, as there is no speaker identified during the first instances of conversation), and is located here:
http://www.amazon.com/Mysterious-Isl...der_B005U3V380
Don