Mercedes Benz 300 SL Roadster Chassis no.: 7500248 engine no.: 7500245 Reg no.: UnregisteredRoadster version of the Mercedes-Benz 300sL will be introduced at the Geneva salon opening on March 17, 1957, the basic design is similar to that of the 300 SL' This new model will be in the production in the spring of next year' first news of the 300sL Roadster. 'The Autocar', November 23, 1956