The first car Melkus built was VW based, and is pictured on this page (top right):
http://www.melkus-motorsport.de/moto...x.php?navid=22
The 2nd car was Veritas, with a 6 cylinder Alfa motor. I assume it was a pre-war motor, as 6c1500, 1750, 1900, or 2300...or pre-war 6c2500 motors would have been much easier to come by than a post-war 6c2500 in 1952. The motor was under 2 liters, so it is impossible to tell what it was without a S/N. It is also possible that a post-war 6c2500 motor was used, reduced in displacement, but again, I think it would have been easier and cheaper to find a pre-war motor in 1952. The Alfa motor only lasted a few races before it blew up, and was replaced.