I think it's a little difficult to be 100% with an answer due to the corrosion. It looks perhaps a Watson Company mark, see: http://www.925-1000.com/americansilver_W2.html But try to clean up the area around the mark, hopefully that will give a clearer indication.
Hi, I was thinking of Watson Co, but the sward within the wreath cannot be seen.Possibly if cleaned, as suggested. The company made silver mounted glass.