As usual there is some great knowledge here. Thank you all for sharing. Quite a surprise to me about the authenticity.
Thanks for the advice not to cut the sheet. No worries. I won't be cutting it.
KK Nice find. How did you acquire it?
My father was a prominent businessman and had a great working relationship with his bank. They knew he was a collector and often kept oddities and other goodies aside for him. I expect this was one of them.