A superb UNMOUNTED MINT MISPERF ERROR block of 6. A superb UNMOUNTED MINT MISPERF ERROR block B41180" is in sale since Monday, March 18, 2019. This item is in the category "Stamps\Great Britain\Elizabeth II\Decimal (1971-Now)". The seller is "bbstampsltd" and is located in Basingstoke. This item can be shipped worldwide.