Which of the owner of Portstewart Football Club is a former Northern Ireland international footballer and manager?
Portstewart F.C.:  The club's home ground, Mullaghacall, was officially opened in 1997 by Harry Gregg MBE. Harry Gregg: Henry "Harry" Gregg MBE (born 27 October 1932) is a former Northern Ireland international footballer and manager.
Harry Gregg