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).