You may have have given up (it is 6 years since yo posted your frustration) but, as I wanted it for my teaching, I researched and found out recently that the only copy is available at the Shakespeare Institute in Stratford upon Avon to be seen on their premises. I saw the play in the thetare and it was quite special. I have no idea why they/RSC are being so precious about it. Even the Director of the play told me he had no idea. This should be publicly available. It was such a watershed event. Hope this helps.