Searching for the parents of James Matthew Blunt born @1880 in Indiana USA

I have only two documents: James marriage certificate and death certificate.


Information on his marriage certificate dated 30 June 1917 has James as being 37, father as John Thomas Blunt and May/Mary Cunningham but the mothers name is difficult to read so it may be different to Cunningham.
James married Madolin"Dora" Collins nee Webber in Australia.


Both James and Madolin died of the Spanish Flu on 13 June 1919 in Newtown, NSW Australia.
They left a 14 month old son Leslie James Matthew Blunt later adopted/fostered and renamed Leslie Charles Saunders Willcox.


Leslie was my grandfather and passed away 25 June 2012. We would like to include his parents names on his headstone as they were buried in unmarked graves.


I have been unable to find any birth information, immigration to Australia or voting records.
Trying to ascertain James accurate birth details. This has proven difficult due to birth records starting in Indiana after 1880.

ANy information or suggestions would be greatly appreciated.