Shepherd's whistle
They are also produced commercially. Simple whistles may cost less than 1 USD in bulk; expensive ones may be quite ornate. They are commonly made of plastic, aluminum, stainless steel, silver, brass, titanium, Corian, jade, buffalo horn and other materials.
Henry Arthur Ward
Of the British whistle makers, he was the only one that seemed to have made cast GSWs, though they may have been made at B Lily & Sons in Birmingham, since they were one of his main outlets for selling whistles in Birmingham and also made cast patterns in pewter and Britannia metal . It may be noted here that B Lily & sons were located at the same street as J Hudson & Co at the time and sold other makers but Hudson's. and supplied whistles ordered from Ward, De Courcy and T Yates among others.