I found a set of NOS .020 oversize pistons for my GMC 270 project. (ELCO brand made in Austria) They came with rings & piston pins but unfortunately the piston pins are a little tight in the pistons. Measuring with a bore gauge they're either zero clearance or .0001" interference fit. The manual calls for them to be hand selected for a "hand press fit" which I would estimate to be .0001 clearance.

I could take them to a shop and have them honed, but is there a good way of honing them at home? I hate to use a flex hone.

I do have an old AMMCO small bore rigid hone that has 3 holders that hold replaceable emery paper inserts. The directions for the tool tell how to hone pistons and rod ends so that's what it was intended for.
Anyone ever use one of these hones? If I try it I'm guessing it would be a good idea to practice on a used piston first.