I have 3 sets of gushes. All VDO. Some Speedo’s go to 120 MPH and some 150. Some gauges have plastic and other glass faces (prefer the glass). I hooked up my wireless drill with a square bit and they all read approximately 35 MPH. Guess they work? Any info is appreciated. I see serial numbers on the top edges.

Have a great night.
Brett

One common failure is the odometer. I recommend you test the speedometers again with your drill and look tho see if your mileage increases. GLWTS

I love the silver dot gauges with glass, especially those native to the 914-6.

Is there any adverse affect/benefit to value if you carefully tape, sand and reshoot satin on the bezels? Didn’t
Know if it devalued and older gauge to do so.

Also, how do you test the tach?

Unless you have electrical test equipment lying around, the easiest way I've found is to hook it up to the car (at least for a functional check). You need +12V, GND and the tach signal. Good luck.

- Tony

Do you know if by sanding and reshooting the bezels satin hurts the value of the gauges? I know that sounds a ridiculous question bu sometimes original with patina and a little rust might be more desireable?

Thanks