My grandmother left Sydney in March 1931 for England (having married my grandfather, who was British, two days before). I'm not sure if she will therefore have travelled under an Australian passport or under a British passport (as his wife)? Does anyone know?
In addition, does anyone know if passport records from that era were kept (and still exist)? I've been asked to provide details of her passport as proof of Australian citizenship (in order for my father, her son, to obtain Australian citizenship), but I think this seems a bit of a long shot! Any help or advice greatly appreciated.
This is not what you are asking for, but I had a bit of a look online and wondered whether this whole passport vs citizenship situation is not really straightforward as Australians were already British citizens in the 1930's:
“Australian nationality came into existence on 26 January 1949 when the Nationality and Citizenship Act 1948 came into force” (see e.g. https://en.wikipedia.org/wiki/Australian_passport ; https://en.wikipedia.org/wiki/Australian_nationality_law ; https://www.passport-collector.com/evolution-australian-passport/ ; https://dfat.gov.au/about-us/publications/historical-documents/Docu...).
From what I can understand, being an English born UK cititizen or an Australian born UK citizen could give you the same passport in Australia in the 30's.
PS here is a NAA guide to available passport records: http://guides.naa.gov.au/more-people-imperative/chapter12/passport-...
(but I don't think that it contains what you are looking for)
Maybe an "passenger departure inquiry" might be an option as it might prove nationality (don't be amazed if it shows "british citizen"): https://reftracker.naa.gov.au/reft100.aspx?key=02PassDep
Thanks very much for your help, Sylvia!