Los-Nr. 979

10 c. green, two singles with oval "CCNA / Cartagena" cachet in violet and tied by cds. "CORREO AERO CARTAGENA 21 JUL 1920" on return Flight cover of the "Santa Marta" to Barranquilla, front with additional franking 3c. as pair, one stamp cut along frame and few wrinkles, small tear at left of cover, otherwise a very rare and attractive commercial usage