It sounds to me like you need to look for the sort of reamers that are sold by machinist tool suppliers. I've got an old set that go up to an inch, but larger sizes are no doubt available. Mine were made by Hjorth in Waltham
Ma and have an interesting design. The length of the reamer is a specific diameter which can
be increased by turning a screw at the end which causes it to gradually expand. One could
easilily scrape a hole larger by the thousanth of a mm. with them.
Starrett is still around I'm sure and they would still offer a version of these. Check machinist's suppliers.