Bradey & Hubbard Slag Glass Lamp circa 1910

This beautiful Bradley & Hubbard lamp was a wedding gift to my grandparents in 1909 or 1910. The base is really beautiful with flowers and the finnal or top piece is an interesting shape. I would like to replace a couple of the slag glass panels as they're chipped at corners. Does anyone have an idea of a good source for antique slag glass panels? Many thanks!