Original Mint Sheet of 50 “Boston Tea Party” 8 Cent stamps. EXTREMELY RARE OFFSET PRINTING ERROR. Part of the image was printed on the back of the stamp sheet. These errors are extremely rare and even rarer on complete, intact sheets. Prices: Our prices are very tightly calculated and are very fair. Please do not ask us for discounts as the answer will always be “No”. Authenticity: Every coin or banknote we sell is guaranteed authentic. You’ll receive an invoice with your item(s) that can be used as a guarantee. Grades: We try to describe our items as detailed as possible. Please look at every picture we upload to a listing. Our high resolution pictures show best what a coin or banknote looks like. You’ll always receive the exact item(s) pictured. We don´t give a guarantee on grades that a third party grading company would give a coin or a banknote. Listing and template services provided by inkFrog.