So far as can be told, Master Kilby has been found once only in tradition; Cecil Sharp noted it from Harry Richards of Curry Rivel in Somerset, in January of 1909. That's all we know; it doesn't seem to have been published on broadside sheets.
Benjamin Britten published an "art music" arrangment of it, but you can be pretty sure that anyone who sings it now learned it from Nic Jones' recording, at one remove or another.