This Australian aerogramme (Stein A-21), the 10 d Christmas 1964 issue, was posted from the Australian Antarctic Territory (Wilkes A.N.A.R.E. 10 FE 67).
The 1 c stamp was added to make up the 9 c aerogramme rate after decimalization, which took place on February 14, 1966.
Conversion table
Pence Cents
9 8 | |
10 8 | |
11 9 |
Sent to the Polar circle, Sweden, via Stockholm (transit postmark 3 Mrs. 1967) to receive special postmark (11. 3. 67, on reverse). Philatelic.
Credits
The original post contained an error. I mistook February 14, 1967 for the decimalization day. In fact, it was February 14, 1966. This one year difference made it necessary to revise the post completely. Thank you, Erwin, for pointing me to the mistke.
Reference:
Stein,The Aerogrammes of Australia and its Dependencies, 1944-1980