Well Sandchip; It looks to me like a punty rod was used and that it was coated with hot glass that was not applied to the center of the bottle and obviously moved after application. It is a neat old bottle because of the cold mold ripple in the glass and the extra glass on the applied glass finish. That glass had to have been too chilled in the tooling process, to reduce the thickness and shape the taper. As a bottle it obviously held the product. This product was made before Quality Control was important.
It is a bottle I would like to study and have in my collection - but that isn't going to happen. RED Matthews