After looking around ebay I found a meter that was inexpensive and I thought would like good for an "old timey" clock.

DC 05V Round Analog Voltmeter Voltage Panel meter DH62 Neednt with Shunt http://r.ebay.com/TFlw4T At $9.00 each with free shipping from China, I was a little hesitant on the quality. After about a week they showed up. First thing I did was test out the calibration. Well guess what it was pretty far off. All in all I had to do a number of modification to each meter. In order of execution.

1. Open up the meter and remove the measurement panel
2. Remove the crappy wiring and calibration resistor
3. Drill a 1/4" hole in the middle of the back, so that a WS2812 LED can be mounted later
4. Drill a 1/16" hole above the 1/4 hole for access to the 10Kohm 10 turn pot. To calibrate the needle
5. Wire the negative terminal to the top side of the movement
6. Connect the center and one of the wipers on the pot to the + Terminal
7. Connect the other side of the pot to bottom side of the movement
8. Put the new measurement panel on. Made in power point and printed out on cardstock
9. Close it up.
10. I then calibrated using an Arduino sketch were I type in a PWM value (0 to 255). Calibration consisted of setting the PWM to zero and then using the cam to set the zero point. I then set the PWM to 255 and adjusted the pot to full scale.

/*
Quick hack to test meters
*/
#define OUTPIN  (5)
char  pwm_val = 0x00;
String in_cmd = "";


void setup() {
  pinMode(OUTPIN, OUTPUT);
  Serial.begin(57600);
  Serial.println("Meter tester started");
  Serial.print("PWM out on pin ");
  Serial.println(OUTPIN);
  Serial.print("PWM initialized to: ");
  Serial.println(pwm_val, DEC);
  Serial.println();
  analogWrite(OUTPIN, pwm_val);
}

void loop() {
  while (Serial.available())
  {
    Serial.print("cmd] ");
    in_cmd = Serial.readString();

    pwm_val = in_cmd.toInt();
    Serial.println(in_cmd);
    Serial.print("PWM set to:");
    Serial.println(pwm_val, DEC);
    analogWrite(OUTPIN, pwm_val);
  }
}