Snuffy - I have the BBC (Burton) version and the original NY premiere recording (Dylan Thomas and 5 American actors). I'll have a listen and see what I can do.

Incidentally the notes on the NY recording say:
"...when Nancy Wickwire came to Polly Garter's song, Thomas fully expected the song to write itself. He had no notion at all of what he thought he would hear: Make something up, he told Nancy. She did; and he was so moved by it that when she sang it at the end of the play, slowly, mournfully, he inserted into his script the direction, A Long Pause"

Mick