Walker and Hall trophy cant make out if it is Silver or not

I have a Walker and Hall Trophy from around 1958 and I want to know if it is Silver or not. It does not have a hallmark as such but attached is a photo of the bottom of it. It weighs 556grams (17.87 Troy Ounces) so I am hoping that it is silver. If you would like to see a photo of the trophy please ask. Thanks for looking. Lee