Great photos, very helpful.
What we do know:
- the bottle was blown in a 3-piece mold
- age is most likely early 20th century
- used for liquor, most likely whiskey. This is a generic bottle sold in bulk to distilleries or bottling plants.
- the glass has etching or staining from being buried or exposure to water.
- cork top.
I cannot quite tell if there is a purple tint to the glass - if so, this indicates the presence of manganese in the glass. You will find a number of discussions on this forum on that topic. You said light blue - that would be unlikely. Possibly the bottle was picking up reflected color from something blue nearby.
The WW marking on the base is a mystery. It is possible (just a possibility) that this is the mark of Thomas Wightman and Co. from Pittsburgh. PA. or a sucessor. This glassblower used a similar "W" marking.
You will see numerous labeled examples online - check out this ebay search result: https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR0.TRC0.A0.H0.Xlabel+pontil.TRS1&_nkw=labeled+whiskey+bottle&_sacat=0
The value of such bottles are in the label. Unfortunately the plain bottles are darn common...