I believe it is an S. The tank measures 3.5 tall x 4 wide x 2.5 deep. The height from bottom of tank to top of spout is 6.5 tall. Has measuring stick and has control for 1 pt. 1/2 gallon or 1 gallon. The 4 screws that secure the pump to the tank are missing. The finish has some scratches and spots from age, also some of what looks like paint overspray. There is a plaque on the bottom that reads 369. Please inspect the pictures closely as they are part of the description. The item “Rare Vintage S. F. Bowser Gas Station Oil Pump Salesman Sample” is in sale since Monday, April 02, 2018. This item is in the category “Collectibles\Advertising\Gas & Oil\Merchandise & Memorabilia\Other Gas & Oil Memorabilia”. The seller is “gooddealdaves” and is located in Brownsboro, Texas. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Russian federation, Israel, Mexico, New Zealand, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica.