DO NOT SEND IT TO SEIKO! They don't provide any service for vintage that is worth the money and if there are any parts of the movement needing tlc they don't have the parts. Most retail jewelers claiming to service watches aren't much better than than a battery change kiosk (neither of whom would I trust to actually do battery changes in my 7548's or Citizen divers). Most retail watch makers are focused on Swiss and while they should be perfectly capable of servicing a 6309, will not IME do as proper a job as someone specializing on Seiko. I would recommend trying Daniel Blair at the BlairWatchProject and consider jeweling the arbor ports as part of the service.Now I just have to figure out the best way to go for servicing. Find a reputable jeweler locally that can do it, or send it to Seiko US in NJ? I looked at the Seiko site and it looks like the starting cost (assuming no issues) is about $270.