That's been tampered with, and is definitely not a proof.
Cute idea. There are so many stamp designs that could use a little help I'm going with Innocent Correspondent, myself. Cheers, /s/ ikeyPikey
There is only one proof and that is in the Royal collection, and many modern replica proofs (posthumous proofs) issued by the post office.
Hi Rob So it may be possible that the one I have is a re-issued posthumous post office proof? Anyway it is a nice talking piece. Horamakhet