After seeing a better photo I'm even more convinced that it's an early flavour bottle. Doesn't look like any straight-side that I've ever seen. Usually when you get a weird Coca Cola bottle like that it's a flavour bottle. Also they were using the hobbleskirt design for Coke bottles in 1918 so I doubt that they'd still be making more straight-sides.
so I heard from Terra Haute Indiana historical society museum, they have told me the bottle dates back to 1915 and is a original coca cola bottle that was actually filled with coke. this bottle was manufactured in root glass company and only a few were made. the mold that was used made the bottles have cracks in them so the mold was stopped from using.
From what I've always been told, Only Coke bottles with Coca Cola in Script contained Coca Cola. All other Coke bottles could of contained anything else but Coke. If this is True which many think it is then that makes Unscripted Cokes worth very little. Your bottle in it's poor condition maybe worth $1.00.
Yeah, the thing with historical societies and museums is that they generally don't have that much specialized knowledge on everything that they display. They can't, there's just too much knowledge out there for the few people that work there. I can't imagine that anything about that mold would cause cracks in the bottle, it's just a generic mold. There were thousands of them used across the country.
Also, here it is straight from the Coca Cola company itself: " The Coca-Cola Company required that the bottlers emboss the famous Coca-Cola logo onto every bottle." http://www.coca-colacompany.com/stories/the-story-of-the-coca-cola-bottle