Berlin Airlift

On a recent trip to England, my father-in-law very thoughtfully bought me a packet of stamps. Included was this oversized cinderella commemorating the Berlin Airlift.
I assume it's British issued because of the interesting perforations on the vertical side, which I've seen before on Machins.
So, what can you Cindy experts tell me about this baby? Also, what about the perfs, what kind are they?
Thanks in advance.

That's a nice one! Is that one of those RAF flying boats tht they used to land on the wansee river instead
of at Gatow airport? The airlift is quite an interesting time in history both philatelicly and otherwise.

A quick ebay search and I have the answer.
A 1999 commemorative label.