Hi d12016466, Your cobalt bottle looks like it has a pouring lip - which makes me think it is an ink bottle. Looking at the bottom picture - the off center circle tells me it was made on an Owens machine. This can be confirmed if it looks like it has sweeping curved texture that was created by the glass shear mark on the bottom of the parison form.
RED Matthews
I hate when people do things like that, shoot or break old bottles. I found a good Cobalt ink by the river but it was broken in a way that made me think someone was bored and smashed it on a rock for the heck of it.