The 2023 Summer Auction - Sale 340 Day 4

1884 (Mar 31) Hong Kong to London registered cover, bearing QV postal fiscal 12c on $10,the proper registered rate should by 20c, so this cover underpaid by 8c, but was stamped with a 62B obliterator and accepted without penalty. The 12c on $10 postal fiscal was used to meet a temporary shortage of the 12c stamp late in 1880, and is extremely rare used on cover. This cover is unique.