I wasn't able to find a Bert Lloyd recording. I did find a Hungarian recording of "Fehér László balladája" with an entirely different melody:

https://www.youtube.com/watch?v=R7S9cXRvAwU

And another:

https://www.youtube.com/watch?v=8JSNu63i6vE

Here's an English-language version by "Boxer John" which does not use the usual Judy Collins melody (but it doesn't use the Hungarian melody, either):

https://www.youtube.com/watch?v=Mulig1B55kQ

The song was collected by Bela Bartok, and A.L. Lloyd translated it into English. Was Bert Lloyd also the composer of the melody Judy Collins made popular?

-Joe-