I have never seen that one and I have collected Cod Liver Oil bottles for many years so I probably would have noticed it. The glass stopper is not common, altho they do show up from time to time. I wonder if it might be English, or a medical product not for home use. Maybe someone else knows.
I did find one for sale on line. They mention salts cure medicine. Saline is a liquid, so must have been a salt water quack cure? Definitely from GB.