Hi, I hope you had success with your endeavour.
My colleagues and I are going through the exact same struggle now. We've also contacted other theatres who staged it successfully, but only one got back to me and sadly, though she told me they staged an adaptation, she couldn't supply specifics on whose adaptation or how they secured permissions for said adaptation.
Did you have any luck? Could you please share with me your secrets, if so? We are getting desperate and there are rumours that someone else in our theatre community is going to run away with our idea before we can make it official - - and we have such delicious ideas, too!
Ever grateful for your help, if you can.