Vintage Seamaster passed down from Grandfather, help appreciated

I recently received this Seamaster from my grandfather and would appreciate any help with providing more information about the watch. It is very sentimental to me and I am hoping to learn more about it. I know he has had it for a long time, I am not sure how long but he is in his 90s. Between the bottom buckles "18k gold" is stamped. The bracelet is stamped "14k" and also "Z&F". Also, I am in the Atlanta area if anyone could recommend somewhere I could take it to have the caseback removed and the watch possibly cleaned and serviced. Thanks!

I'm definitely leaving that to a professional.