Robert BARR died in 1919 aged 78 at Inglewood. Parents were John and Ann BARR... mothers maiden name unknown. Mothers name could be an error, very common.
Francis BARR died in 1886 (on registration index) , yes in Sandhurst. He's buried in Bendigo Melanie, interment number 010483, unsure which cemetery this is but there is a heap of Barrs buried in Bendigo, go to http://www.bencemtrust.com.au/ and you can send them an email to find out more. You can also search their database of all the Local Bendigo cemeteries. If you find out where he is etc. there might be a headstone? I do my shopping in Bendigo every Thursday i can go and check it out and take photos if you like.
Here you go Melanie
BARR, Francis Christening
Gender: Male
Birth Date: 3 Apr 1829 Birthplace: , Beith, Ayr, Scotland
Recorded in: Beith, Ayrshire, Scotland
Father: John BARR
Mother: Jean GILMOUR
Source: FHL Film 1041335 Dates: 1701 - 1855
Found that on Vital Records.
and this one same parents:
BARR, Allan Christening
Gender: Male
Birth Date: 11 Mar 1837
Christening Date:23 Apr 1837
Recorded in: Beith, Ayrshire, Scotland
Father: John BARR
Mother: Jean GILMOUR
Source: FHL Film 1041335 Dates: 1701 - 1855
Hope that helps!

As for Robert BARR;
BARR ROBT aged 21 arrived DEC 1863 on ship GREAT BRITAIN could be him. It's the only one i could find close in age at all.
Sorry i can't be more of a help.
Thanks
Kate Finning
finningfamily@iinet.net.au