Thornwood and Carol, and Jim,
Thanks very much for your suggestions.
Thornbill, you may be right about the 1950s. Because I’d never known him looking so young I thought it must have been even earlier, but he was only in his late twenties when he got out of the army and it may have been within the next five years that the photo was taken. He may have aged a lot from the time he left the army until the late fifties, which was when my own awareness of him would have been starting to form.
From the early 1950s, Uncle Jack lived in Newcastle with his mother until she died in 1971. His last few years he lived with my family, my parents and me, a couple of suburbs away.
Sadly, Carol, all the time I knew him he looked older than his age, much older than his sister (my mother) who was five years older than Jack. In my first memories of him, when we visited grandma, his hair was receding, his face (I realised later as I grew up) was alcohol ravaged. Unfortunately I don’t have other photos of him (that I’ve found anyway).
Missing from the badge/button is a wire clip which long ago rusted and fell off - you can just see the holes it fitted into on the back. I have a vague recollection (or my mind could be making it up) that for a period of time at some tourist places you could buy such things. (?)
And, Jim, thanks very much for your expert input. (I was about to post this and go to bed - way past time - when I saw your post.)
Thanks again all of you, for your interest in and thoughts on this topic.
Cheers, Peter.