You wrote: "...Joseph Keller, born 25 Nov 1872.
He died on 20 Oct 1936 & his death record from New York, United States, states he was born in Hungary on the date above ..."
That birthdate didn't come from his death certificate (which has no date of birth) but from Joseph Keller himself when he gave it to the WWI US draft registration board.
Your Queens County NY thread:http://boards.ancestry.com/localities.northam.usa.states.new...
I'm happy to see that you now have the likely place of his birth.