4 Shillings as proof on matt reddish brown in the vertical, centered prefolded lower margin strip of four, unused with full original gum - same three stamps even mint never hinged! The besides a block of four largest known strip unit is in wonderful fresh, all around wide margined in outstanding quality! Photo expertize Brettl and photo expertize Dr. Christian Mozek BPP with accordingly appreciation\". Impeccable. Very rare proof. Only still approximate 38 pieces condition. \" - unique Museum piece!