Amp gauge shunt

Ok, I guess that is technically correct, but would it be functional? How would you know what the ampmeter scale was? As I am writing this, I am thinking that there is no scale on the ampmeter anyway, so maybe I don’t really have a point....

LOL. I've heard that A body ammeters were supposed to be somewhere around 40-45A full scale, but I bet that was never officially printed anywhere