"From the very beginning, Liverpool has been a mixed race community. Most of the first settlers were men, almost without exception, including the black Loyalists from the American War of Independence."
Ray is deeply respectful of his own ancestry, which can be traced to shoemaker Frances James, the son of a Scotsman who married a black woman in Hamilton, Bermuda. Their son, Edward, came to Liverpool in the 1850s, and married Harriet Gates of Barnton, Cheshire, a Quaker.
Ray was the son of Edith and a white RAF man, Francis Costello. He was their only child, brought up by his mother and great auntie Agnes, who was married to Henry Brew, a Ghanaian seaman.
From Granby Street School, Liverpool, Ray advanced to the CF Mott Teachers' Training College.
He taught at Windsor Street School and Harrington County Primary, both Liverpool, before becoming a special needs teacher. He was awarded a masters degree in education in 1980 and then became the first person from the old black community to be awarded a Phd in education from Liverpool University.
Thus he qualified for entry into his own book, a truth that he acknowledges with characteristic modesty, as he pours the tea at his suburban semi in Aigburth, laughing with a long, deep rumble, which trembles the fine crockery.
These days, Ray is a writer and adviser on the education of black children. His book, The Early History of Britain's Oldest Black Community, 1730-1918, is used in libraries, schools and universities.
"I like to think of my new book as a community biography along the lines of a national biography - Churchill under C and so on," he says. "Black children in Liverpool schools haven't been provided with sufficient role figures. If they cover black people, it is Martin Luther King, Muhammad Ali, etc, but Liverpool with such an old population deserves its own history.
"Some years ago, research was done which showed that very few people, white or black, could name an eminent black person. My purpose is to provide people with an education about the Liverpool black community."