Yes, In Praise Of John Magee was sung by Robin Morton on The Boys Of The Lough's 1st vinyl, called simply 'The Boys Of The Lough'. It is A side, track 2, IIRC.   Not sure if it has been reissued on CD, but would imagine so.

It begins, "I sing in praise of John Magee, who was auctioning his wife"; and contains the lines "It was on a fair day morning she gave him some old jaw, So he said 'now I can auction you according to the law'." Exactly what OP is seeking, it would appear.

~Michael~