I didn't find the song in the Traditional Ballad Index, or in the Digital Tradition.

Here's the Peggy Seeger recording. I think she got it from her mother Ruth Crawford Seeger's "American Folk Songs For Christmas"

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

Here's the Pentangle recording that seems to be best-known among Mudcatters, although I wasn't familiar with it:

https://www.youtube.com/watch?v=rEQxBPdIOh0

Because Sandy Paton was such a powerful influence in the early years of Mudcat, it's his version I know best. I'm having trouble finding a full recording of the version he recorded with his wife Caroline, but here's a really interesting clip that starts with that song:

https://www.youtube.com/watch?v=u7d_TYaDNkA

Oh, here's their recording of "Watch the Stars/By'm By"

https://www.youtube.com/watch?v=Zu6KEXCx4pQ

Unfortunately, some of these videos may not be playable in the UK.

-Joe-

(lefthanded, I hope you don't mind my combining threads)