Just for clarity, there have been GB booklet panes issued without perforations. For instance...

These booklet stamps were issued with imperforate horizontal edges and do not have any additional value over a normally perforated stamp. Some other booklet panes were issued with imperforate vertical edges too. This particular 14p booklet pane has no value other than containing a perforation variety of the 14p stamp. As an entire pane it is worth very little as it shows trimmed perforations on the right side which is why it has been used for recent postage.
The stamps posted by
BaeiouZ do not fall into the category of missing perforations or issued with imperforate horizontal (or vertical) edges.