small piano technician's tool

This odd little tool was also found amongst the 'storage locker pipe organ tools' (already shown mostly) and was well on its way to becoming an 'unsolved mystery' post of its own, when I (or more accurately Google...) accidentally solved my own mystery -- so I thought I'd go ahead and show it anyway -- mebbe y'all will also enjoy, and/or mebbe it'll help solve somebody *else's* mystery sometime in the future...? ;-) :-)

Its a little steel tool measuring about 8" long. Its shaft has a blunt square ground tapered point on one end, the other has a little sorta oval-shaped 'hollow socket' on it, and the 'handle' part inbetween is round and also very gently tapered towards the 'socket' end. In its middle the letters "H.S. & Co. N.Y." are stamped in small letters.

Googling that shortly produced images of similar-ish tools, which are apparently used to adjust parts of the "action" mechanisms inside pianos. This website mostly sealed the deal about 'what it is', though doesn't really explain exactly 'what it does' or how to use it (esp the pointy end?) or who/what 'HS & Co' is/was. No matter, I'm still comfortable labeling it as a piano tool.

http://mshepherdpiano.com/antique-piano-tools/regulating-tools-fixed-handles/

Other meandering around that site also suggests that -- in fact like 'old pipe organ tools' do as I've already mentioned -- old 'piano technician tools' also tend to find their own way from toolbox to toolbox over the generations. Thus I'm also reasonably comfortable in believing that this one would date from the late 1800's-early 1900's (during the 'heyday' period of piano production/sales/usage in the USA) no matter who might have first made or used it.