A 250C is a carburated Coupe. The VIN sez it's a 250 6cyl gasser. It sounds like it has a 220D motor. Motor swap back in the day + whatever badge the guy had lying around, just for fun.

BTW, the badge is on the wrong side. Thus lending credence to the "badge swap" theory.

I think I'll rebadge my 300SD as a 420SEL or maybe add 6.9 badging just to confuse everyone when I sell it someday...