I know that this is a longshot, but I will try anyhow.
John McGuire died in Somerville, New Jersey on 3/13/1916. He was approximately 80 years old and was a native of Ireland. He worked on the ferryboat "Red Jacket" for the Elizabeth and Somerville Railroad and for the New Jersey Central Railroad retiring ~1906. He never married and lived in Somerville, New Jersey for the last 45 years of his life.
His obit states that he had a sister living in Ireland and several nieces and nephews living in Franklin and Somerville, Massachusetts
I would like to find the descendants of these nieces and nephews in Massachusetts, if any survive, who might be able to clear up a mystery concerning his claim of Civil War service in the Confederate Navy.