The 2019 edition of the ACSC states "A used example with perforations misplaced 5mm to the right is known". The stamp illustrated in the ACSC is a single 3d brown KGVI with the left side imperforated. The vertical pair above is the MUH example of the same stamp with the 5mm displacement but with both sides imperforate, it is unrecorded and is considered rare.
