I have several Seiko 5s, the oldest is around 20 years old. Never been opened. The trick is to use them in turn regularly. I also have an inherited Omega whic

I have several Seiko 5s, the oldest is around 20 years old. Never been opened. The trick is to use them in turn regularly. I also have an inherited Omega which is 60+ years old. This was serviced once when I got it, 25 years ago.