First of all, thanks a lot for all your replys.
[quote]Reverend Rob: The number and 'AR' indicate the goldsmith and region, in this case Arezzo. […] If it is a very thin watch, what is inside may be a micro-rotor movement.[/quote]
This is great information. I´m excited getting to know where the watch possibly has been produced respectively my grandfather may have bought it. Some research on the web led to this site:
http://www.silvercollection.it/SILVERSMITHSAR.html
If I´m not completely wrong this page may contain the name of the goldsmith and some interesting data?
The watch´s thickness is 1.05 cm (~ .82 cm without the glas).
[quote]William Smith: Is the watch case also hallmarked for solid gold?[/quote]
There is no hallmark on the outside of the watch case. Maybe there is one on the inside?
[quote]Geoff Baker: If the box you show is original to the watch my guess would be it dates to the 1970's or 1980's. I wonder if there is a logo on the clasp of the bracelet. To accurately date this beauty we would like to see a photo of the inside of the case back and one of the movement as well.[/quote]
Unfortunately I cannot tell if the box is original to the watch. But there is one detail about it forgot to mention. One of the lid´s sides has a circular dot printed on it. I´m not sure if this means anything?
There is no logo on the clasp, neither on the outside nor on the inside.
No logo on the clasp, no hallmark on the watch case … maybe the wristband is custom made, as some of you already suggested.
I´m going to let the watch case be opend and take some pictures next week.
Thanks again! I will keep you all updated.