The date comes from pdmusic.org (as noted by Genie, thread 4074, 23 Aug 01.
In PDmusic, the reference given is M1621.W.
"I'll Twine 'Mid the Ringlets" is followed by [No. 57] [1860, 1888].

Perhaps these references will help you.
My other suggestion is to send an Email to the site (they have answered questions and corrections I posed to them promptly and courteously). Just click on the Link Benjamin Robert Tubb at the foot of pages.