US Stamp, Plate Number Block of Twenty, Scott #1498a (1489-1498), Eight Cent Postal Service Employees Tribute Issue of 1973. The Stamps are Mint, Never Hinged With Original Gum with Very Fine Centering. 2024 Scott Specialty Catalog List Price is Four US Dollars. USPS Standard Shipping to the US is Free. Canada Shipping Via USPS First Class International Letter is $2.50.