Barry, I have this song on "Folk Songs of Olde England Vol 2" by Tim Hart and Maddy Prior, but they call it "Turkey Rhubarb". They sing only the words that you have (almost), then repeat it as a catch.
Turkey rhubarb, Turkey Rhubarb, Turkey Rhubarb I sell, I come here from Turkey to make you all well, Don't you all know me, oh me name it is Dan, For I am the celebrated Turkey Rhubarb man.
The CD is produced by Mooncrest Records, Twyman House, 31-39 Camden Road, London NW1 9LF
Both volumes 1 + 2 have some great stuff on them.
Regards, Anne