Oil dispensers were made by just about every gas pump company, plus a number of oil equipment dealers. It is not a Mobil dispenser, just like a Coca-Cola truck was not made by Coke, it was probably made by GM. Mobil or a Mobil dealer was who bought it.
Somewhere on the oil dispenser there should be a ID tag, this will tell you the name of he company who made it. My first Gas Pump Identification book contained many oil dispensers, but most were dropped from the revised edition to make room for more gas pumps. If you find the name of the manufacturer, go to my website:
www.petrolianacollectibles.com then to Gas Pump (and more) literature, then to the company. There is probably a picture of the unit on the website
If there isn't a ID tag, please post a picture of the unit here, one of us should be able to identify it.
Jack Sim