I just purchased a Radial Wrench from Giovanni at Tryphon. What a fantastic tool for removing the section on pens you are restoring.... I was very pleasantly surprised at how easy it was... a lot simpler than the old "spark plug" wrench I had been trying... the feel is a lot better, you can really feel the section coming loose and it is almost impossible to twist the section and crack the barrel...
OF COURSE, you still need to be careful.... it is not a miracle tool.. but it does make life a bit easier...

I also picked this tool from Gio in Philly, and it is awesome.