Bob, plastigauge is not the most accurate means of measuring a crank journal. Any oil, dirt, or contact of any kind in any other journals is going to give you a false reading. Don't get me wrong, I use it and rely on it for approximations. For real accuracy you need a good Mic.
With the #'s you gave I would have no qualms at all by using the crank as is. But hey, that,s just me.
FWIW, $.02?
Mongo