I also have a gold cage of a lady hand watch (the watch has been long gone). This cage matches the signs show in the picture listed by Nessa. The watch cage I have as the same marking of a S G and a key in between and also has the the 2 horse heads marking and has a S/N of 72741., therefore I assume that this was made on 18K gold?
Rating
similar hallmark and watch by: Anonymous
I have the same hallmark and the numbers 26525 on a ladies pendant watch 2.5 cm (1"). The back is green enamel with 17 gold shamrocks. Probably of French origin.
Rating
Watch Appraisals by: Anonymous
thanks for writing in however due to the large number of jewelry hallmark questions we are receiving unfortunately we are unable to provide free opinions for watch marks at this time.
You might like to consider having the watch appraised by the experts.