Thanks for posting Chris!
You might want to check post 11. The version from the album Summertime has the melody in Eb concert which is C for the alto. That is the key I put the waltz accompaniment in as well. There are also some nice melodic ideas in the solo transcription in one of the links.Why we doing this in C? I've just been trying to borrow some licks off Mr Desmond and he's in Eb. I'm off to do a bit of transposing.