I just was reading how to reset the gauges if you know where they run when the engine is warm. You'll be real close but maybe not 100% accurate.
Engine warm. All needles removed, except speedometer with should of been reset at zero anyways. With the key on running and no needles replaced yet. The Tach if it idles at 750 or so, lightly set the needle on the stem @ the desired running rpm and press on. Same with all the gauges. OP, volts, temp should be fine, but fuel might be a problem as you may not remember where it was exactly. When the redlight for fuel warning comes on, you could always reset that particular needle. Otherwise all the others should be close enough for electric gauges, as long as you remember where they operate and set them back accordingly. Hope that helps some.
That came from one of the gauge face suppliers for those who have done as you have done. See you aren't alone, that's for sure. Seems common enough that they wrote about it.