cover 3c Blue on blue entire (UO11), UPSS #PD48a (Thorp #6066), size 10, knife 53, wmk. 2, unused, printed return address and penalty clause, some toning which is insignificant on an item of this importance, otherwise extremely fine for this great rarity, with 'R.H.W. Co.' backstamp, Scott retail $16,000.00photo est.