Nice Stamp – See Scans for Details & Condition. See Our Store for Many More Stamps, New listings Added Daily. The item “US, SC# R66b Used, XF 90 PSE Graded Cert, CV $5500.00″ is in sale since Monday, June 05, 2017. This item is in the category “Stamps\United States\Back of Book\Revenues”. The seller is “suncoaststamp” and is located in Sarasota, Florida. This item can be shipped worldwide.