Excellent article as always.
Looking at the dates listed in the 'Particulars of Completed Ships' and the document held in the Public Records Office of Northern Ireland, the document held in the Public Record's Office lists all of the five 'pay dates' (Keel laid, Frame to Height of DB, Hull Plate complete, and Delivered date). Meanwhile the 'Particulars of Completed Ships' only has the 'keel laid' and 'Launch' days. Don't know if this equates to anything but I found it interesting.