1971 (07) Literary Anniversaries - 'Triple Drawing' Cover - Duke of York's School CDS - PRE-DATED ERROR

Very rare 'Triple Drawing' Cover with the full set, cancelled with a Duke of York's School CDS - But it is a PRE-DATED ERROR....

The CDS is dated 28th JU 1971 - the issue was 28th JULY, so 1 month pre-dated.....

Not something you are likely to see often as the only other error on this issue is a pre-dated Kings Lynn CDS, and even that is a one-off..........

Code: 61247