Prototype Harley-Davidson Servi-Car with an XA Powerplant

Here's another interesting prototype motorcycle from the WWII era.  Basically, Harley took a servi-car and swapped the 750cc side-valve v-twin engine and chain-drive transmission with the drivetrain from an XA motorcycle.  The XA's drivetrain borrowed heavily from the German BMW R71 and featured a 750cc side-valve opposed-twin engine and an enclosed shaft drive instead of a chain.  This provided several advantages over Harley's typical set up including a cooler running engine and less maintenance (due to the shaft drive).  It looks like it would have been a good set up, but the copyright issues that arose over the XA's drivetrain helped to keep this motorcycle from going into production.