Sierra Leone: Mixed Pre-Decimal and Decimal Franking

This is Sierra Leone (Müller/Sehler #7)  6 d  Climbing Lily
 
The new currency 1 Leones = 100 c with 1 Leones = 10 s = 120 d  was introduced on August 4, 1964. 

The aerogramme was sent from MAGBURAKA, 10 SP 64. It was uprated with a 2 c stamp, a pre-decimal/decimal mixed franking.


References
Müller/Sehler, Aerogramme Afrika 2012.