A little update on this Kyusu :
After much research , aided by several friends in Japan , I've (they've , really) discovered that this item is actually a Choshi (Sake pot) , rather than a tea pot .
One Japanese collector believes that this item was from a 'high-end' location in the "Water Trade" industry (AKA the 'Floating World') .
Nothing solid to confirm this 'water trade' origin yet , though .