C6(1Sep1949) has Scott watermark 228 (multiple small crown and CofA). C7(6Dec1956) is unwatermarked.
Hold the stamp up to the light, if it has a C of A watermark it's 1949, if there is no watermark it's 1956.
How does one go about telling the difference between an Australia C6 and a C7 ? Thanks in advance
re: Australia question