A Newfoundland 1927 60c De Pinedo flight stamp will headline the sale of the Jack M Shartsis collection at Kelleher Auctions.
The lot is expected to make $30,000-40,000 when it crosses the block in New York on March 29-30.
Just 33 mint examples of the stamp are known to have survived to the present day, placing it among the rarest and most desirable Canadian issues.
Only 300 were ever printed. They were intended for use on airmail flown aboard a plane piloted by Italian aviator Francesco de Pinedo.
This present example is in extremely fine condition with a well-centered impression and fresh margins.
Another example in comparable condition made $45,000 at Spink New York in January this year.
A Newfoundland 1932 Airmail $1.50 on $1 Dornier DO-X Flight inverted surcharge is estimated to make $20,000-30,000.
The stamps were printed in blocks for use on mail travelling aboard the Dornier DO-X flying boat on its return flight from Canada to Germany.
Around 8,000 were printed, 50 of which display the inverted surcharge.
There are thought to be between 20 and 40 surviving specimens of this rare error, with the example offered in the sale considered among the finest known.