Exactly...when you introduce different resistances it either becomes a headache to calculate or a pure crapshoot. I was hoping you'd pull out a slide rule and say "oh we just need an extra shunt with this rating ______ and a new face plate showing 100 amps (or the understanding 50 now equals 100).
I didn't realize that either until I was hunting for an old fuel gauge and saw this one. Ah well, as I've said all the predictions/warnings of Mount Vesuvius didn't happen in any way so it probably isn't worth too much worry. Maybe this winter I'll convert the ammeter to a voltmeter and just be done with it.
Thanks again for your thoughts and comments.