So, my starter is a randomly picked, untested 1.9 starter that was in a pile
of them some years ago.

Lately, the bus simply won't start. I get great power to all the
accessories, the battery appears to be holding and charging just fine, but
the thing just won't turn over fast enough to be of any value. I've cleaned
all my grounds, I've tightened all my leads, and yet.... no dice.
Jumping the battery off another car no longer has any effect.

I'm starting to think my starter is a bad egg. Any thoughts?
What type of symptoms would be expected from a failing starter....if other
than what I described?

-Craig