Nope, no idea
You need someone with expertise on "stamp reveal"
and. you need Bobby De la Rue or Fairdinkum stamps (the experts)
Could be anyone of these perhaps
632 looks the best bet, but Postmarks can make fools of us all.
602 Redgate (Alexandra) doubtful
622 BRIDGEWATER ON LODDON
632 MIDDLE CREEK (GLENGOWER)
642 BEAUMARIS (GYPSY VILLAGE) (SANDRINGHAM)
652 DRY CREEK
662 AMBLERTON (CLIFFORD)
672 UPPER MAFFRA (MAFFRA UPPER) (NEWRY)
682 GARVOC (YALLOOK BRIDGE)