About a month ago I ordered panel truck rear glass and instrument cluster glass from http://www.classictruckglass.com
The pieces arrived well wrapped and look good.
You might want to call them to place the order as the website shopping cart seems a bit "wonky".
I think you want around 7 volts from the alternator to charge the battery. If your meter is going "crazy" when you check for direct current voltage perhaps your alternator has a bad diode, regulator, or you have a grounding problem. Try checking for alternating current from the alternator. In...
I have a 6 volt positive ground alternator in my F-3. The ammeter in this truck is the stock induction type meter. The ammeter shows that the system is charging right after the engine is started then gradually tapers back to the "neutral" position.