cover front franked with 1862 24c Red lilac (70), prepaying the single-weight rate to the UK, red "New York Br. Pkt 19 Apr 17" datestamp applied initially crediting the UK with 19c for British packet paid mail, then re-weighed in New York where it was found to be over ½ ounce so black "N. York Br. Pkt 10 Apr 17" and "Short Paid" in oval handstamps were applied, carried aboard Cunard's Java departing New York April 17 and arriving Queenstown April 27, while on board struck with the very scarce "2/-" due handstamp, backstamped Hull upon arrival, stamp and front both with small faults, still fine and rare use, the 1849 Anglo-US Treaty only allowed for unpaid or fully prepaid mail, partial prepayment was ignored with such mail being treated as wholly unpaid