I have found another record for Thomas Arthur Goldsmith in the National Archives: GOLDSMITH THOMAS ARTHUR : Service Number - Q203783 : Date of birth - 20 Feb 1894 : Place of birth - RAMSEY ENGLAND : Place of enlistment - MOUNT TAMBORINE QLD : Next of Kin - GOLDSMITH EMILY
Access status: Not yet examined Location: Canberra 1939 - 1948

It looks as though he re-enlisted for WW2, although these records haven't yet been put online (but can be bought from the Archives).
recordsearch.naa.gov.au/SearchNRetrieve/Interface/DetailsReports/ItemDetail.aspx?Barcode=4909662

Sue