An OUTSTANDING 1917 Scott #506 Block of 4, 6 cent, Red Orange, Washington XF, NH, OG with pencil notation on 1 stamp.  Please see scans for centering and the condition of the gum. The SMQ value for this block in this condition is $240.00.  Shipping is free and satisfaction is guaranteed.   I also have outstanding fine crystal items, vintage baseball and football cards, and high-quality unused U.S. stamps coming up for sale or auction on eBay.  Please let me know what you would like to see listed.