I don't think it was a lamp when it left the factory, but it could easily have been made into one professionally by a separate, third-party company. It wasn't uncommon for (often quite small) lighting, metalwork or woodwork companies to buy in glass vases (or decanters, candle shades, glass slabs, etc...) from quite good companies for other uses in the 1960s-70s. Over the years I've had a couple of Grønland vases that have been converted with lovely sculpted teak and rosewood parts - one even had the original third-party label, but that was several dead computers ago so I don't have a record of it.
That the Gulvvaser turns up with a few different fittings and mounts would indicate a number of third-party companies were doing this.