Canada #5, 1855 6d slate gray Prince Consort on wove paper with original gum,
to quote the 2008 Sergio Sismondo certificate:
"The stamp submitted is genuine, unused, with original gum. It has large margins on three sides, unusually large at top and right, showing a tiny sliver of the adjacent stamp at right, but is cut into frameline on the left half of the lower margin. The stamp has impeccable freshness, and is free from hidden faults or repairs at the time of examination. Mint six pence stamps of 1852-1857 with fresh and original gum are very rare."
This stamp was Lot 24 in the 1965 Robson Lowe sale of the General Gill collection. The Gill collection was the finest and most complete for mint Canada Pence ever offered. Full original gum, lightly hinged. CV as fine $30,000 (as VF $70,000), Scott US$25,000, SG £21,000.