Thank you. I'm still looking for a suitable strap for it. Also, I just had it serviced, and I realized that the crowns have the JLC logo instead of GP. Would this help in determining the year this was produced? When it was opened, I didn't see any inscriptions inside the case back.

I apologize for reviving this thread two years later. You see, I just pulled out a Gyromatic 9443 HA out of my storage a couple of weeks ago. I could not find much information about it, but your post was quite helpful. The watch was given to me by my mother over 30 years ago, when I was 12 years old