Greetings, gentlemen (and perhaps one or two ladies?), Recently I discovered that one of the pivots broke off of the balance staff on my model 21 chronometer. I'd like to replace it myself, and do have a fair amount of experience on replacing staffs in pocket watches. Since I paid around $400 for it to serviced about 15 years ago now, and don't want to duplicate that bill if I can avoid it, I'm going to attempt the repair myself. I am of course, proceeding slowly and cautiously, as I don't want to damage the nice chronometer movement. I don't plan on doing a complete service on the clock, so I won't be taking it down all the way. Instead, I figured I'd just replace the staff and see how she runs. After all, it was serviced professionally 15 years ago, and hasn't seen a lot of running time, maybe 30 days total. Surely the modern oils used, etc., should still be holding up, no? I may also have to replace the impulse jewel, as it look like it has a chip out of the center. This may be why I'm seeing a black fuzzy substance on the escape wheel teeth. I'm just guessing. Maybe I'll even need to replace the escape wheel because of this? I'm sure that if I paid a professional, the cost would be somewhere around $700. It's a nice timepiece, but I really don't love it that much. Right now I'm stuck on removing the hairspring. The manual calls for a "wedge tool" of some sort, but a screwdriver doesn't seem to be of much help. Does anyone know of a decent stand-in for the proper Hamilton tool? Thanks for any help, guidance, suggestions, warnings, etc. Cheers.