The error stamp has a short perf at bottom. I always obtain a certificate of posting. Member of the Philatelic Traders' Society. The item "5d LITERARY LIGHT GREENISH BLUE OMITTED SG 827c Cat £800 UNUSED ON FDC" is in sale since Friday, October 17, 2014.This item is in the category "Stamps\Great Britain\Elizabeth II\Pre-Decimal (1952-1971)". The seller is "capital-collectables" and is located in London. This item can be shipped worldwide.