I don't know how skungy it is, but the key is NOT to remove the oil film,
which volatile solvents will do. If it is clean enough to check the lift
with a micrometer, it is definitely clean enough. As the other poster said,
greasing it after the inspection is good but if you do clean it with a solvent,
don't use anything more volatile than kerosene, which will also leave a slight
oily film. It is possible to grease something that is "too clean" and
entrain moisture under the grease, which will also allow the item to rust
under the grease. In plating they refer to a "water-break free" surface,
which means that all the oil has been removed so that water easily wets
the surface. This is important for plating, but just what you DON'T want
for storage, especially if your storage area is humid. (like my storage room
in Panama!) In fact if you could get by storing it under your bed, it would
be better unless you have dangerous dust bunnies. Usually they are noncorrosive, though.

BTW, examine the shape of the lobes carefully, looking for lobes that are
rounder or less square-shouldered than others. There should be NO curve
in the axial direction - the lobes should be as high on the ends as in
the middle. They should all be of the same height also.
--
George Downs Bartlesville, Oklahoma