My car reads in mph but the dial goes all the way up to 320mph. I have a little "mph" sticker over the bit on the dial where it used to say "kph".
I have a Thor delimiter fitted which I want to keep. I'm sure it'll just be a wiring issue to get the speedo reading the right thing. It'll look into it.
The light dimmer doesn't affect the brightness of the dials. (It does affect the odometer though). It wouldn't surprise me that the wrong resistors had been fitted though (any ideas what the right one's should be?). The previous owner was a total billy-the-bodger. (Scotchloks, mains wiring, wires twisted together and taped ... oh the list goes on ...)
Regardless of all this, I still want my name down for a set of these dials which best suit my car.