French Colonies Senegal 1926 Postage Due Cover Morocco

envelope addressed to French Morocco, bearing Yvert 72, 5c black & carmine and Yvert 73, 10c green (2) tied by St. Loius datestamp, underpaid and bearing French Maroc Postage Dues Yvert 30, 20c olive applied and tied on arrival by Casablanca Maroc datestamp. Nice combination. (pt)    ID: 32109