I found a source of nice, vintage, Ford-scripted ammeters. I am into Model A's and T's and this ammeter is originally a Model T gauge, but it comes with 12-volt resisters so it can be used on our trucks. What could be cooler than a retro-style Ford ammeter??? They come LED-lighted and unlighted. Just thought I'd share.

Fun Projects, Inc. - Model T Ford and Model A Ford Parts

 

Nope! Can't do it.
That does look pretty cool. I like the look, but don't even think about connecting it up to one of our vehicles. Not unless it's got a Model-T charging system. Which you hope it doesn't of course!

Unlike the later shunted ammeters, or the early Bronco (and truck?) ammeters, this is a "direct reading" gauge. That's where the current it's reading actually flows through the gauge.
Very dangerous for your wire harness' (and truck's) health and well being.

The Bronco ammeters (and presumably the trucks too, but I've never pulled one out of a pickup dash) were "inductive" and had a loop on the back that the wire ran through. Like a timing light's inductive clamp, it simply reads the current by the magnetism/magnetic waves (or whatever the proper terminology is) and cannot be overpowered by too much current.
A shunted ammeter, like in our later '70's trucks did not read the current directly at all and only used small gauge wires to carry a percentage of the current that the gauge interpreted for our eyes.

Either of those is generally safe, but the gauge you posted up is why ammeters fell out of favor for the safer volt-meters. Fires behind the dash will do that.
Our inductive and shunted ammeters were perfectly safe, but the 20a model-T version is simply a fire waiting to happen on a modern vehicle with a 45 to 250 amp alternator.

Sorry if you knew that already. Just wanted to point all that out in case others reading this thought they look cool too.
Now, if they come out with an inductive-loop type that has at least a 60a or maybe even a 100a scale, I'm all in!

Thanks for finding it.

Paul