Death certificate, Tasmania 1917, will record birthplace.....years in the colony
(if born elsewhere).....age at marriage/s...children numbered as male, female, alive, deceased.
When Morven dies, 1917, his wife Susannah is still alive, and would likely be the source of information on his death certificate, even if she is not named as informant.
Use this web site Graves of Tasmania -
http://www.gravesoftas.com.au/to locate an image of headstone, St Marys Anglican Church Cygnet, for Morven, son Arthur Clyde (KIA 1918) and separate headstone for Susannah, died 1942.
Morven is described as died 65th year which would encourage you to think that his exact birth date is known to his family?
Interesting that with several sons, some of whom have two given names, that his name Morven is not continued to his own family. Just something to note.