I ended up just picking up some Mobil 1 high mileage full synthetic. Ran motor flush through there in the oil, drained it, poured a fresh quart through it, filled it back up.. It's doing fine. About 400 highway miles so far and haven't lost a drop... very pleased, thus far.

Of course the drain plug fell into the drain pan. Then of course I put the drain plug back in without realizing that the o-ring was still in the drain pan. YaY.