I'm sure Kevin will chime in when he can, but the odometer thing is sort of a visceral reaction to someone putting all of their spending money into a vehicle restoration and wanting it zeroed out in ever way. Including mileage.
Personally, even though I did the same thing to my first car when I was a teenager, I don't like the idea anymore. I prefer honesty in advertising, including the blemish of high mileage on a vehicle. Frankly, to me, the higher the mileage is on an old truck like ours, the more street cred I think it has. After all, how many EB's are running around with 200,000 plus miles? Not many I'd wager. And hard to know anyway, which is another reason for keeping it honest.
Under a certain mileage (let's say 50k for example) the bragging rights are that your old rig has super low mileage for it's age. But for me, once it gets over 100k it's bragging rights in reverse. You get to tell stories of how many bazillion miles yours has!
I have no qualms at all about saying proudly that my '71 has 175,000 miles on it. I just hope I can get over the 200k mark sooner rather than later!
For the ammeter-to-voltmeter swap, more and more are doing it. There are two primary reasons, but only one in my book. The main reason anyone would want to change to volts reading is that after upgrading to a higher amp alternator (pretty much anything above 70a) the ammeter becomes just so much garage art. It no longer functions (safely anyway).
That's my main reason. I personally prefer an ammeter (or would rather have both actually) but by far most people understand and prefer volts vs amps. To this day most newer owners don't know what their ammeter is supposed to do. Voltmeters have been in use instead of ammeters pretty much since the late '80's in Fords at least.
And good riddance too, to those "shunted" ammeters that hardly ever worked! Ours on the other hand were direct-reading inductive ammeters and were very reliable and accurate and consistent. But only good up to about 70a or so, and with the popularity of 130a and above 3G model alternators, the old ammeter wire just was not up to the task.
Better safe than sorry then, and switch over to the volt-meter in it's place.
Hope that helped out with the info you needed. Fallingdown will have to let us know just how many he personally does for members here, but I'm sure it's at least a few.
Paul