Volex pendent light shade

After years, I finally have a couple of these Volex shades. This is what my primary school had in the old part of the building in 1978 when I first started but within weeks they were replaced with 8ft Thorn 100w pop packs with diffusers. I can't remember what flex they had but the ceiling roses would have been large ceramic type. I don't think they were original to the building as it was built in 1911, perhaps it was the classic case of the heat from the lamp warranting replacement to the original fittings. One of them is seen here in the hall with a 25w GLS lamp.