Dear Gaby,
To order digital copies from the National Australian Archives check the instructions on teh web page here:
http://www.naa.gov.au/collection/using/order/index.aspxYou will need to pay for the digitisation of records. Immigration documents can give you a lot of information. However it appears that this is probably just a shipping list which would at least tell you if he were travelling with someone else.
This is the name search page. The National Archives provides an index on line but only digitises information if you pay them to do so. To see the digitised documents you will need to register to obtain a username and password.
http://recordsearch.naa.gov.au/NameSearch/Interface/NameSear...You could try contacting the East Gippsland Historical Society to see what searches they can do for you. they might be able to take a picture of the gravestone.
http://www.egfhg.org.au/For surviving family you could try and search the Australian White pages telephone directory:
http://www.whitepages.com.au/You need to enter a location: try Orbost, Victoria or just Victoria.
For historical newspaper records try searching TROVE which is the website of the National Library of Australia. This is the advanced search page:
http://trove.nla.gov.au/newspaper/search?adv=yThis is the Victorian Birth Death Marriage website for historical records. I am not sure if a death date of 1986 is too recent to be indexed on this site. However there is at least one death record for Kuhoff noted. Vic BDM requires that you pay (using credit card) 99cents per apge of results from the index. This is just an index and does not give full details. You can order digital copies (about AUD$30 per certificate) on line and the link for download delivered to you in a very short period of time. Australian genealogy can be very expensive!
https://online.justice.vic.gov.au/bdm/index-search?action=ge...