Those tolerances should be checked with an air gauge not pins if they are serious about 2 tenths. The good news for you if they are checking with pins they will be excepting parts with more than 2 tenths.
Single pass a .159" diameter good luck. You are not going to feed it over a tool that small by hand with any luck. To hold good geometry on a part like that I would "square hone" it on a Sunnen power stroker like a ML2000.
If you buy a diamond stone you also need a hard mandrel. You will spend close to an hour getting it true enough for that little stock removal. Just use an A55 stone, aluminum oxide, and take the tenth out of all 6 in less than a hour. The stone will wear fast enough to stay dead true.
It is a centrifugal pump not much to go wrong. The shaft should have a few thousands clearance if it is more you will have to bore it out and sleeve it. Other than that make sure the pickup screen is clean I have seen them plugged with lint from rags and make sure the belt is not slipping...