One thing that many people forget is the printing press. The pour spout is handy for the household consumer needing to refill they're desk set inkwells. It's lot needed to smear a plate on a press.
It doesn't mean that it can't still be something else though.
While its true it could have been used as a utility for anything I find that most are listed as inks .The one I've showen was a ink that most likely had a brush in it to be used to edge and burnishing shoe and boot soles.There was a case of these paper lable ink some ink lables also on congress water bottles found in an old building in town that was a shoe shop in the late 1800s .So any bottle could have been used for any purpose.I just tend to call them ink because I've seen quit a few labeled as inks .Agian jane that is a very nice bottle.
bill