I wonder if it was a "borrowing" from the old Vaudeville duo of Gallagher and Sheen. My grandmother had an old 78 rpm of the two doing a song in which Sheen began each verse with "Oh, Mr. Gallagher, Oh, Mr. Gallagher..." and Gallagher began his reply, Oh, Mr. Sheen, Oh, Mr. Sheen...". I can't recall an entire verse, but the scansion would fit.
Alas, the 78 is long, long gone.
                                  -George