Hugh Moffatt's original recording of 'Jack and Lucy' - a duet with his sister, Katy - was on his 'Loving You' album on the Philo label [Philo 1111]. It was later reissued on an excellent compilation CD titled 'The Way Love Is'- tracks selected mostly from 'Loving You' and 'Troubadour' albums - on Columbia CD 468965 2. As written and recorded by Moffatt, the third stanza differs from what is given in the transcription linked above by Sorcha:

Where are you goin', Lucy, what you doing girl
Come back here, lie back down
For I want to feel your heart beat
Oh, Lucy, lie with me a while

Words and music by Hugh Moffatt, copyright 1981 Boquillas Canyon Music/Atlantic Music Corporation.

--Stewie.