There is no registered birth for William James Henderson in W A in 1915.
Nor William James Quirk.
His mother's ( Mary Quirk) address (as NOK) changes with in the scope of the WW2 service record from Hurtle Square, Adelaide to Mingenew WA.
Then NOK changes to wife Margaret Thelma in Salisbury S. Aust. She was born 1921 registered at Morphett Vale
Margaret's father was Harold Edgar Jones, a carrier who lived in Salisbury and Kangarilla. There are items in the Trove Newspaer Archive relatiing to his bankruptcy. By the time of his discharge in bankruptcy in 1941, he was an enlisted man. You can see his record.
https://recordsearch.naa.gov.au/ He died in 1987
Margaret's mother was Margaret MacKay
There was at least one son to this couple , a brother to Margaret named Kenneth Roy who died in 1951.
Although none of this information is helpful in your search,it might might be good to have for your records.
ADDING.I have inadvertantly doubled up on some infromation from Cass in the above post. Apologies.
Sue