Canada #506, 509 1970 Northwest Territories Issue and 1970 Expo '70, a Nice Combination Usage on Double Weight Airmail to Germany, March 19, 1970 The Day After Issue

A double weight airmail cover to Germany, sent March 19, 1970, the day after the Expo '70 issue was released, and franked with singles of the 6c Northwest Territories issue and 25c Dogwood from the Expo '70 issue, to overpay the 30c double weight rate by 1c. A nice very early commercial usage of #509.

Est $25.

To gain a better understanding of what I consider in valuing covers, you might find it useful to read the blog post here.