Scott;
Yes, that would likely work.
The actual system voltage would not matter as long as the components can safely handle the voltage and not arc over, etc. For your needs that is not an issue.
You would need to calibrate any home made shunt to the meter. Not important for just a visual on system activity.
You can use a length of #10 copper wire, too. From memory it will drop 1 millivolt per amp per foot [from a possibly faulty memory].
I posted a Diary on that long long ago and if you can find that it might help. I went into fair detail on that posting.
Good luck with it.
Tom