Miller 4 Panel Slag Glass Table Lamp

I was recently left this lamp from my Grandma's Estate, any info would be appreciated. Is it collectible? Are there model / pattern numbers - I collect English China - know nothing about lamps and / or glass. It's 50cm tall. Original cord and plug (its old) What material is it made of - there are rub marks where colour is missing - like paint missing but doesn't look like it's painted. Thanks in advance.