Really struggling to identify the size of what I think is a friction fit balance staff. The ID of the maker of this pocket watch is a real problem so I have pushed the staff out so I can measure as best as I can its dimensions. I was wondering if I can use a pivot gauge to help with its dimensions. I have been using a micrometer and the overall length is 4.893mm BUT both ends of this staff are broken so I guess its size should be 5.0mm+ the shoulder measures 2.132mm. I was hoping if not getting the exact balance staff but to purchase a staff that is too large and to make a fit using my lathe. I have been looking at the web site www.balancestaffs.com but I need more measurements. Any help will be most appreciated .