hey guys - i'm new to this site, and to vintage mercedes - for 15 years, i have been an early aircooled porsche guy with three early porsches - i now own a 1966 w111 sunroof euro coupe, which i really enjoy - here's my problem - i have a stock kph gauge - i picked up a mph gauge to make things easier for me, but the rear of this mph gauge is very different from my stock w111 kph speedo, and doesn't fit right - i have looked online at 190sl, 300sl, w111, w112, w113, etc to figure out what model this mph gauge is from - no luck so far, so i'm looking to an expert here to help me out! - the gauge with the white-ish rubber back is the stock w111 kph speedo - take a look and please let me know what you think! - also, there are two markings on the back of the mph speedo "W151" and "12/61" - thanks again, brad in seattle