I looked again at the New York Times and got some details on his earlier life, based upon his first marriage and the death of that wife.
May 14, 1950 issue: He's elected president of the Essex County (NJ) Board of Taxation (he was already a commissioner), and identified as a real estate broker living in East Orange.
Jan 11, 1951 issue: Barbara Smith marries Edward A. Halligan, Jr. on January 10, and Halligan's sister is identified as Mrs. James W. Kelly, Jr. of East Orange. Kelly is listed as an usher.
April 24, 1951 issue: Mrs. Madelyn Halligan Kelly (his wife) dies at the age of 29 after an operation. Kelly is identified as president of the trucking concern of Ferris & Rossborough, Inc.
August 15, 1951 issue: James W. Kelly, Sr. dies at the age of 86, leaving sons James W. Kelly, Jr. and John F. Kelly, plus 7 daughters, 12 grandchildren, and 8 great-grandchildren.
Jan 3, 1965 issue: Kelly, a widower, remarries, this time to Mrs. Margaret G. Marucci (a widow), an Essex County Freeholder.
Using this information, I was able to use Ancestry.com to find the wedding announcement for his first marriage (January 17, 1948). It identified one of his sisters as Anastacia Elizabeth Kelly, and said that James W. Kelly, Jr. had attended St. Benedict's Preparatory School, and had been a Naval Reserve lieutenant commander in the Pacific during World War II. Kelly's mother was already deceased.
Using Anastacia's name, I was able to locate James W. Kelly, Jr. in the 1920 census (West Orange) at the age of 12. This was the first actual evidence I had for his birth year. He also had sisters named Catherine (born about 1900), Agnes (born about 1902), Josephine (born about 1906 and apparently Anastacia's twin). His older brother John was born about 1896. This accounts for 4 of his 7 sisters, so next I looked at the 1910 census (James was the youngest of the children). This added sisters Margaret (born about 1898), Anna (born about 1894), and Mary (born about 1892).
Finding the siblings or his 2nd wife may help in figuring out what happened to him after 1970.