Did the British really employ magicians and practical jokers?

Transcript
Extract from a letter from a British intelligence officer June 1945

Catalogue ref: HS 6/641

Source a

TOP SECRET M.O.I. (S.P.)
RHT/1981 5 June, 1945.

Lt. Col. Rawlinson
M.I.19 (a).

Dear

As you probably know, towards the end of 1943 we carried out an interesting project with a German 6 pfennig stamp bearing Himmler’s head instead of Hitler’s.

The project was a great success and in due course a German letter postmarked Stuttgart: 23.9.43 was received in Switzerland and had on it between the ordinary Hitler stamps, one of these Himmler stamps.

The Swiss press and other neutral press and stamp collectors and philatelic [stamp collecting] journals all reacted admirably and soon spread the story (as we expected they would) that this mysterious stamp, of which only two or three samples had ever been seen, indicated that Himmler had prepared a coup d’etat [a revolution to overthrow Hitler] and evidently a sheet or so of the stamps had leaked out prematurely and been used by mistake.

Source b

In other words, from the point of view of the outside world the project - which I do not want you to divulge to anyone else - was a howling success. We are now most anxious to find out what effect it had in the Nazi hierarchy itself.

I was intending to have Himmler interrogated on the subject but his unfortunate demise [death] intervened.

I would, therefore, be grateful if you could arrange a suitable question to be put to one or two of the senior generals who were close to the Himmler entourage [followers] and Nazi hierarchy during the last four months of 1943 and the first few months of 1944.