This mid-1970s Omega Seamaster Cosmic 2000 (with original box and papers), originally owned by my grandfather (of course), has never worked right. Over the last decade I have attempted to get it serviced by various local to Florida watchmakers -- without success. Issues range from running 5 minutes fast per day to the second hand skipping beats to a grinding feeling when setting the time and date. I want to try one last time before giving up for good and hoping to get recommendations on vintage Omega miracle-workers. Due to sentimental reasons I am willing to go all in almost regardless of servicing cost or location. Who is generally considered the best at fixing the unfixable?