Hello Dominic, Yes the glass was intact, I have just heard back from him. He says he did not think it was glass?
The poster has been, for want of a better word "glued" to some thin card, but is starting to come away quite nicely. My main aim is to find a restorer who can do it justice now. The only problem being I cannot fold, or roll it. So it may have to be someone in this country. I may have to send a test poster to them first, unless anyone knows a first rate restorer in the U.K.