Don't think so, Michael. The Stromlinienwagen was, IIRC, the full-bodied, single seated Grand Prix car (hence the absence of headlamps).The 300SLR was a two-seater sports car designed to win the then World Sports Car championship (drivers were so much more versatile then!). the 300SLR was indeed the car used by Stirling Moss and Denis Jenkinson to win the 1955 Mille Miglia, Jenks unrolling his route guide on what looked like a toilet roll and signalling to Moss by hand what was coming up. But this isn't it! This is:

http://www.idcow.com/mst2069.html

P.S. My nomination for the world's best-looking competition car is the Jaguar D-Type of the same era.