Chuck has really hidden his light under a bushel, and it's almost impossible to find out what he did. Even the newspapers of 1944-1945 have ignored his DFC, despite making a big thing of publishing nearly all other DFC's earned.
However, we can glean that he flew Spitfire Mk XI's with 681 Sqdn RAF in Burma, largely doing reconnaissance photo work, under the noses of the Japs for most of the time.
Here's a bio (below) of one of his Sqdn mates, one Ronald Charlie Gardner - who has produced a photo of a PRU training course, where "Chuck" Younger is shown standing in the rear left top corner of the group.
I have little doubt that Chuck's exploits were very similar to Ron Gardner's, seeing as they were both flying Spitfires in 681 Sqdn in Burma, and both won DFC's.
Ronald Charlie Gardner - biography
Further research reveals Chucks DFC notice was posted in the Commonwealth of Australia Gazette, dated 6 September 1945, on Page 1923, position 15.
It was also published in the London Gazette, dated 17 August 1945, on Page 4187, position 12.
As neither of these publications are available online, the records need to be physically scrutinised in the relevant libraries that hold copies of these Gazettes.
AWM record for Charles Irving Younger