For the record:
Response from Paula.
Hi Rod,
Thanks for that.
In fact Burdon was sold in 1932 to Luis Caballero who used the label till the late 1980s.
Could it be that your stamp was a back label?
(I could not answer that query, it has one wondering why they would perforate a wine label

)
Unless it was the easiest separation method, at the time.
Perhaps the printer was set up with a perforator.
Volumes of labels, cinderellas exist perforated from Spain.