This search is for 24018769 SIG L.H. Jefferies Royal Signals. His GSM, with Malay Peninsula clasp, was found in a house in Canberra. It is believed that someone by the name of Jefferies lived in that house, but not recently.
I've had no luck with any enquiries back to the Royal Signals Association nor through some other contacts I have. I have one option which I'll try next week but in the mean time here are some pictures of Jefferies' GSM.