temp gauge markings

Damn, I was hoping this would be something simple. Would it be possible that the gauge came from a different vehicle and as such would be calibrated different? I believe the engine on the dyno ran 80psi oil pressure, it was at warm idle in the picture but pretty much goes to the top of the gauge when running it. Is there any way to test it, or recalibrate it other than removing it from the car and sending it somewhere? I may temporarily put in a aftermarket temp gauge that reads the actual temp, but I like the look of the stock gauge/instruments so would like to keep that in the long run.