Cacheted exhibition cover for the Michigan Stamp Club's 61st Annual Exhibition in Detroit. Circular exhibition cancel reads DETROIT, MI 48226 and is dated MAR 1 1975; a U.S. 8¢ space se-tenant pair (A Decade of Achievement) is tied by the cancel. Front blue cachet bears the legend "The Pioneer Mission to Jupiter." Reverse is blank with no address or written message
Notes for Cover Collectors: • High-resolution scans of front and back are provided; use zoom to inspect postmarks, cachet details, and backstamps. • No third-party grading; condition is shown in the images.