Hi Daniel
Thanks very much for your input, today I did get an e-mailed reply from Orrefors, which states the piece was a limited edition in 1969 however they have not elaborated on how many were produced, and yes the engraver was Bertil Gustavssen. I've tried to download a few more pictures with reference of the marks involved on the base of the vase. I must just say though "Bertil" has really shown his talent as an glass engraver, when you really look at this piece in close up it does not take long to realise it is truly wondrous piece of art from a real master of his trade. How would you price a piece such as this? I've really got to think about this because if anything it needs to go on my contents insurance. Regards Den