It looks to me as though the lettering has been drawn by hand, rather than using a stencil or mould. For example, if you compare the ‘H’ in whiskey on the two jugs, they are different, the one on the Highland Special example has a sloping horizontal. Also the lettering looks to be different heights and sizes, even from one letter to the next in places. I don’t think that would be accounted for by distortions when making it if printed or using a mould or stencil etc, it looks freehand to me.