Great Britain Philatelic Society

S.G. 572 with double perforation at the bottom. It is a genuine stamp- see left side of the stamp- there is a slightly doubling of the perforation. I can not find nothing in Specialised catalogue Vol. 3. Can anybody give me more informations? How high would be the catalogue or selling price? Thank you very much for your help!

The image seems to show that the stamp has slightly trimmed perfs along the top edge, which suggests that it comes from a booklet. Does it have upright or sideways watermark? I would not like to suggest a price for this item but would not expect it to be more than a few pounds.

It is from a booklet. The watermark is upright.