You didn't say when Martin died but if he died after January 1, 1906 I suggest getting his death certificate from the PA Div. of Vital Records. His obituary may not list his parents but might his siblings.
Check with the Northumberland County Historical Society for the obit and any info they may have on the family. Also they may be able to find a baptismal record for him (the 1900 census has him born in March 1939).