1949 GREAT Postally Used Envelope: "VIA HELICOPTER AIR MAIL" [Van Nuys, Calif]

Description

This is one of the best vintage mailing envelope designs I've located:
(1)
The envelope was mailed from Van Nuys, Calif. "VIA HELICOPTER AIR MAIL,"
(2)
Postmarked in Van Nuys on 3/7/49;
(3)
Addressed to the "U.S. Immigration Svc." in San Diego;
(4)
Illustrated with a cartoon of a U.S. helicopter mail pilot flying over Van Nuys and reads "Hello Friends! This is a
["first" which was previously blocked out]
Flight Air Mail Letter Direct From Van Nuys, The Capital Of The Great San Fernando Valley,"
(5)
Below the "VAN NUYS" star reads "Sherman Oaks" and "Hollywood," and
(6)
The return address is written in black pen.
Condition
: The envelope was neatly opened along the top. See my listings for more unusual and interesting items.
Multiple purchases are combined with one postage charge.
All items are shipped sleeved in plastic, and sandwiched between sturdy cardboard.