Spink is auctioning 1,110 lots in its Collectors' Series Stamps sale, which takes place next week from April 15-16.
Among the auction's numerous philatelic highlights is a historic surcharge stamp dating back to British Ceylon, now known as Sri Lanka.
Issued between January-March 1885, this 10 cents - originally 16 cents - Watermark Crown CC stamp is billed by Spink as "one of the great surcharge rarities."
Bearing the image of Queen Victoria, the "good colour" pale violet stamp has 14 perforations and is unused, with traces of gum on its reverse.
Sold with a Royal Philatelic Society certificate, this fine piece of British colonial philatelic history is auctioning with an estimate of £4,000-5,000. (Stanley Gibbons has priced the stamp at £7,500.)