Looking for a 1976 A-body A38 police certified speedometer

The certified only applied to the calibration of the gearing, not the speedo itself, if memory serves.
Is this for a restoration, or for accuracy needs?

I have a 200 'mph' speedo but I don't think it's certified. I know it's actually a metric speedo but it doesn't have units on it, so it's a 200 mph speedo now.