As these things tend to be, found on youtube. Given its age it is in the public domain. It has been released by any number of labels in various remasters and from various sources. A good remaster can be found at the none profit "Immortal Performances" whose site you might want to check out if your looking for a CD version. Alas, I have no idea the source of the version found on youtube.
Lohengrin
Lohengrin........Lauritz Melchior
Elsa.............Elisabeth Rethberg
Ortrud...........Kerstin Thorborg
Telramund........Julius Huehn
König Heinrich...Emanuel List
Der Herrufer.....Leonard Warren
Metropolitan Opera Orchestra and Chorus
Erich Leinsdorf, Conductor
König Heinrich...Emanuel List
Der Herrufer.....Leonard Warren
Metropolitan Opera Orchestra and Chorus
Erich Leinsdorf, Conductor
Recording Live; January 27, 1940, New York
