It is not often that I get to speak to someone who knew a WWI veteran well. In this case the second cousin of 20810 Leslie Manson Juster is in his 90s and was able to provide quite a bit of detail about Leslie on top of that in the service record. I now know that Leslie didn't have children of his own and was one of the early RACQ road side service mechanics.
Thanks to Graham Docksey (scroll down the page to see Graham's details) who sent me the medal. The returned medal tally is now 1492.