An attractive single weight airmail cover to Germany, sent in what appears to be December 1968 and franked with two hibrite singles of the Hydrological Decade issue, and a single of the Henri Bourassa issue, to make up the 15c rate. Slight scuffing on the face of the cover, but still fine.
Est $8.
To gain a better understanding of what I consider in valuing covers, you might find it useful to read the blog post here.
