Never heard of it, but it sounds like it should work.
You probably an get a used Yanmar gauge from Sailorman (Ft. Laud) or some of the other "used boat parts" places, with a little patience. Then it is just a question of whether you need a sender, or a connection to the alternator, and you probably can fix up the original system too.
Thanks for the suggestion and pointing me toward the Sailorman site. I have several items which I would like to find used replacements for.