I have not been on this site for a long time, but I remember this song being discussed some years ago. I learnt the song from my mother, her father was a cobbler and he sang it to her when she was a child. The only difference from her version and Tommy Makem's is the bit of the chorus, Tommy sang " With me robo, robo randy , and me lap stone keeps beating away". The words I learnt are " Ould wax-end and heel-ball your boozing again , and me lap stone keeps beating away.
Wax end was a cube of hard wax that a cobbler would use to make the twine stiff and water resistant. The wax cube was held in one hand while the thread was drawn through it with the other. It was about the size of a piece of billiard chalk. Heel-ball was a larger piece of harder wax, it was heated over a candle to soften it a little and used to burnish the heels by pressing the wax through the layers of leather that made up the heel of the shoe or boot. As a child I helped both my grandfather and uncle in the shop and prepared the twine many times. My grandfather also inserted (using glue) a little stick of wood into the centre of the sole about the thickness of a match. This little piece of wood attracted any water to one spot on the sole preventing water damage to the entire surface. It did not make the sole waterproof but water resistant..

I did discuss this with Tommy Makem himself when I met him in Toronto, he was not aware of these lyrics,but I don't think he changed his version anyway.

Hope this is useful.