South Africa 1937 Coronation Pigeongram Cover with Charity Label

SA: 1937 CORONATION PIGEONGRAM: Commemorative envelope for this Pigeon Post organised by the Hottentots Holland Homing Union. The event was organised in conjunction with coronation celebrations in order to raise hospital funds to which end the envelope additionally bears (applied to few of these covers) 1d "Help" charity fundraising label. Franked pair KGVI ½d's tied by Strand cds 12 MAY 37, numbered "116". VF, attractive, scarce.