You may have already seen his death and funera lnotices in TROVE
https://trove.nla.gov.au/newspaper/article/131674572From The Canberra Times, 3 Ocotber 1968
DOUGLAS, Thomas Harold. — Octobcr 2 at his resi-dence, 76 Wakefield Gardens, Ainslie, beloved husband of Mary, aged 69 yrs.
FUNERALS
DOUGLAS, the relatives and friends of the late Mr Thomas Harold Douglas of 76 Wakefield Gardens, Ainslie are respectfully informed that his funeral will leave the Presbyterian Church of St Andrews, Forrest, after service to commence at 2pm tomorrow Friday, for interment in the Returned Soldiers Portion of the Canberra Cemetery.
Cemetery records:
http://www.canberracemeteries.com.au/grave-searchDOUGLAS, THOMAS Woden Cemetery, buried Friday, October 4, 1968 Plot: H-EX-E-129
Electoral rolls show:
1954 both Thomas (contractor) and Mary at Bong Bong St, Dapto
1954, 1958 both at 12 Eighth St, Narrabundah (ACT), his occupation - painter
1963 both at 76 Wakefield Gardens, Ainslie No occupation shown; perhaps he had retired by then.
Mary died 14 November, 1982 and is buried at the Gungahlin cemetery.
Electoral rolls show Mary at the Ainslie address 1977, 1980.
Her death notice:
https://trove.nla.gov.au/newspaper/article/130829619Judith