The IRA delegation included Sean Mac Stiofain ( Chief of Staff ) , Daithi O'Conaill , Seamus Twomey , Ivor Bell , Martin McGuinness and Gerry Adams . The delegation included Gerry Adams , Martin McGuinness , Sean Mac Stiofain ( IRA Chief of Staff ) , Daithi O'Conaill , Seamus Twomey , Ivor Bell and Dublin solicitor Myles Shevlin .