Canada #360 4c Purple Violet Caribou, 1956 Wildlife Week Issue, Block of 4 on July 1956 16c Overpaid Airmail Cover to Denmark

A very fine 15c airmail cover to Denmark, overpaid by 1c. Sent in July 1956 and franked with a block of 4 of the 4c caribou from the 1956 National Wildlife Week Issue. Unusual usage of a block of this commemorative issue to pay the foreign airmail rate.

Our estimate of the value of this cover based on the above factors is $10. To understand how we have assessed the cover and arrived at this estimate and to gain a broader understanding of postal history collecting, I would suggest you read the article linked here. It should clarify the factors that make covers, and this one in particular scarce, and will help you to understand why we have estimated it at this amount.