New York, June 29, 1858, paid 5¢ rate equal to the British Open Mail Rate to Boston.  Per Cunard Line Europa to Halifax then Cunard Line feeder route to North Sydney, Cape Breton Island, Nova Scotia.  Rated 8d due, then re-rated 10d due, apparently 5d (4d stg.) packet postage from Boston to Halifax, plus 5d (4d stg.) for packet from Halifax to North Sydney.  10d due converted to 1 franc, then charged 25 centimes for transport from North Sydney to Saint Pierre, for a total due of 1.25 franc.

Boston, July 28, 1858, unrated, but likely 2¢ paid for rate equal to British Open Mail printed matter rate. Rated 4d sterling packet postage, apparently comprised of 2d sterling printed matter rate, per Canada to Halifax, plus an additional 2d sterling for British feeder line to Sydney, Cape Breton. No Saint Pierre postage marked, but 4d sterling would be converted to 50 centimes, plus 25 centimes for transport from North Sydney to Saint Pierre, for a total due of 75 centimes.

St. Pierre, December 10, 1850, letter endorsed "per E. A. Parkhurst via Halifax" carried out of the mails to Halifax and by Cunard Line steamer Niagara arriving in Boston, January 5, 1851.  Enters the mails as an unpaid letter in Boston, rated 5¢ for distance under 300 miles to Gloucester, Massachusetts.  This letter was sent before the Post Office opened in St. Pierre in 1854.  The letter includes interesting routing information, noting that "[T]he packet leaves for Sydney tomorrow, which will be her last trip for the season, after which she goes to Halifax once a month, as this will be the only means of communication between us until the Spring" and ending with a note to "[A]ddress your letters to Care of Daniel Starr Halifax otherwise the same as usual, that is to me."