Anyone know where I can get a small (1.75 inch max diameter) ammeter for my little 6 volt motorcycle? New, used, old, don't care as long as it works. In fact I might even prefer old and used, just for the look. My biggest constraints are a small mounting area (as I said 1.75 inches is about right) and a small budget (About $20 max, less is always better)

Also, what's your take on volt meters vs. ammeters? Everyone I've gone to about an ammeter has wondered why I'd even want one. Or they ask me what an ammeter is, and direct me to their selection of multimeter testing machines.

I figured with my weak little electrical system, the real-time feedback of an ammeter would be more critical. But now I'm wondering if the volt meter would be more useful to see the overall system 'health'... WWYD?