18 carat gold antique Helvetia ladies wrist watch

I recently came into possesion of this Helvetia ladies wrist watch. My grandmother purchased it when she was living in Egypt and gave it to my mother to pass on to me shortly before she died in 1993. Its manual wind, solid 18 carat gold. I had a jeweler look at it and he said it just needed to be cleaned, oiled and timed(?) to be servicable again. However his reference book had barely any info on Helvetia watches, and I'm having a hard time finding any info on the net. I am sure the origin is European, and the time frame is most likely 1935-1945. Can anyone give me any information about it, and a possible value?