Thanks for the info, that's exactly what I needed to know. I've removed and replaced a few and feel comfortable with that but I'm not too sure about modifying a box to fit a different diameter barrel. I want to be sure I have the right one and put it in just once.
Thanks for the responses. I remember now reading something Ron wrote about this a few years ago. I should have looked back at his blog before I asked the question. I agree with the second primary rule of pen repair "replace only when it's impossible to repair". I'm sending it to Ron.