columbia first flight cover

Lot 561 Newfoundland #C5 1930 50c on 36c olive green Columbia First Flight Cover. C5 stamp is tied by SEP.25.1930 St John’s slogan machine cancel. Parker & Monroe corner card cover is addressed to London England via Harbour Grace (backstamp dated October 9). Vertical and horizontal creases are away from stamp and light overall ageing. The cover is endorsed on front “Per air Mail Columbia / Harbour Grace, N.F. to London Eng. / Sept 25th 1930”. The Unitrade catalogue states that first flights from Harbour Grace command a premium of 20%. Accompanied by a 2009 Philatelic Foundation certificate. Unitrade CV$17,500