Did Godowsky arranged Chopin Nocturne for left hand (one of Nocturnes)?
Did you happen to see a recent programme on BBC4, t-p, called 'The Piano: a Love Affair'? It was an endearing little programme with Alexander Waugh huffing and puffing amiably all over the place and doing that thing that pianists often do, thumping things out with their fingers on every available surface as they pased by. I rather enjoyed it. I think the piece he was trying to learn for the programme was a Godowsky arrangement of Chopin for the left hand, but I'm not sure which piece it was.
A version of Chopin Etude op.10 no. 6 in Eb minor, which, for some reason , seems to be the Chopin-Godowsky Etude which is most often played. Your description of the BBC4 programme is spot on, George !