A friend has a ring watch that she inherited from her grandmother (my friend is in her mid-sixties, so there are some years involved here)
I think it is a Fortis. It has a 17 jewel mechanical movement. No complications or second hand. The case is apparently white gold, as it has never tarnished.
Please take a look at my rather pictures, and help me ID this watch if possible. (Make, when manufactured, model name...in fact anything that you know, or any sources I might try other than Fortis itself.)
Thanks in advance