I don't even know what I'm dealing with, so I've included a picture. I just got an 1800s Rockford that has been running 10 minutes fast. A watch guy tried to get it to keep time yesterday, but he really didn't do much and maybe it's running 8 or 9 minutes fast now. He seemed to tinker with the little screw (I think that's what it is) in the graphic below. So I tried to do the same. I broke the head of the darn thing off. How serious a problem is that? Does it need to be replaced in order to change the speed at which the watch is running? And can it be replaced? Thanks for you answers.