Here are some stamps that most collectors have never seen.
The first three scans below show training stamps that were reportedly used at the U. S. Army Adjutant General School, Postal Division, in Fort Benjamin at Harrison, Indiana.
The 7 cent black airmail stamp in the first (perforated) set indicates that the set was used sometime during this particular rate, which was in effect from August 1, 1958 to January 6, 1963.
The 8 cent airmail rate in the second (rouletted) set was from January 7, 1963 to January 6, 1968, and there never was a 12 cent airmail rate.
The 30 cent special delivery rate was in effect from September 3, 1957 to November 21, 1969.
So perhaps the second set dates from 1963 to around 1968.
Or maybe there were
three different sets made, and the 12 cent airmail stamp was made in anticipation of that new rate? The rate changed instead to 13 cents on March 2, 1974. Also note that the 11 cent stamp is in red; 11 cents was the airmail rate from May 16, 1971 to March 1, 1974. So maybe this 11 cent stamp was the airmail training stamp?
The last scan shows part of a set from... guess which country?
Jim




p.s. By the way, these stamps are not as rare as this seller (unsurprisingly) thinks:
