Vipers Skiffle Group's "The Ash Grove"

This morning, I listened to Vipers Skiffle Group's Don't You Rock Me Daddy-O.  One of the songs included is "The Ash Grove."  I recognized the melody of this; it's a slight variation of the melody for the hymn "Sent forth by God's Blessing."  In the hymnal, the title of the melody is listed as "The Ash Grove."  The melody that the Vipers use is slightly different from what's in the hymnal, and obviously the words are completely different.

I looked it up on Wikipedia, and apparently "The Ash Grove" is a melody that's used with quite a few sets of lyrics.  The Vipers use the words written by Thomas Oliphant, although the liner notes lists it as just "traditional" and "public domain."

I think this is only the second or third time I've listened to this album, and I have a vague recollection of recognizing this melody, but I don't think I actually looked into it last time.  So now I have.