Kim & Ed — Most, if not all the major glassworks in the UK, together with at least one in Europe, made the
Thistle pattern, simply because it had been around for a very long time, and there was always a demand for replacements. I can't tell from your photographs whether it is cut or mould-blown. If cut, and it's not been overpolished by acid, you will find faint striations on the cut surfaces. As you may have realised, the stopper is not the original.
Here's CameraJim's simple and cheap way of photographing clear glass.
Bernard C.
