Any chance of more info on this bottle?

I have just purchased a bottle which I have been told is in-between the World Wars in date, but would value any more in identification. It is pale blue/ green in colour and approx 9.5 inches tall and 4.5 inches diameter across the circular base, which has a 2 inch high punt almost the diameter of the inside of the bottle. The overall shape is slightly elongated onion with 3 inch neck and flattened lip, wider than the neck, with a pouring spout. The bottle has one verticle mould line and the only other marks are a 'seal' in glass applied to the bottle in a flattened bottom circle, within which there is a 5 point crown and the capital E within larger C just below the crown. This has been told to me as possibly being the mark of the contents producer, but not very sure. Whatever the original contents, the punt would collect a lot of sediment, so I am baffled as to the possible contents this glass was made for. Any hints as to the age/ origin of this bottle would be gratefully received. I have noticed a similar crown on the screw top of a modern fortified wine bottle, contents from Spain, if that's any help. Thanks in advance