Answer: The difference is a manufacturing error – picture one shows that the stamp pane has been MISCUT and therefore increases its value to £220.00, from a normal £6.00 catalogue value

There are two ways to identify the ‘miscut’ booklet - You can see the printers ‘cutting guide’ of a red line in the centre of the pane margin in image 1 above ... the cut lines would normally be on either side of the pane’s margin, or they would not be seen at all Also, the 12.5p stamps in image 1 are at the left of the pane and not the right.

Adding to the rarity factor is that printers (& the Post Office) are at pains (and take steps) to try and prevent these "errors" or "defects" from getting out for sale to the public – as you can see, and fortunately for collectors – they are not always successful!!