Vintage Art Nouveau Slag glass Cast metal Lamp with cherub. Very Tarnished

Vintage Art Nouveau Slag glass Cast metal Lamp with cherub. The lamp works fine but the metal is very tarnished. Al glass panels are there and they are not cracked. They look a different probably are not the original ones. The lamp shade is made of lead where it bends really easily. Base has an original cast process hole. The finial is cracking and needs to be replaced. Measuring 17″ ht by 12″ wd shade at widest point by the base is 6″ by 6″.