Lot 50011 – 1863 Registered cover sent to London franked with a block of four 15kr blue, paying the registration fee

1863 Registered cover sent to London franked with a block of four 15kr blue, paying the registration fee and fixed unusually to the front of the envelope, with the scarce « Prussia Registered » with crown mark in red applied in London upon arrival, tying the block, some slight damage to right side, has been opened out, a wonderful usage of these early Austrian issues; cert Ferchenbauer (1997).