Australia airmail 1935 & 1938 4 covers:
1) Australian First Flight Cover 19 August 1935 Australian Transcontinental Airways Adelaide to Darwin. Backstamped on arrival at Darwin.
2) 1st Regular Air Mail to England, (AAMC 826) two different covers : 31 July 1938 and, August 1938, Postmarked Sidney NSW.
3)1938 Australia to England properly franked w. 9d. AIR MAIL/SECTION/GPO machine postmark.