Is this a Shaper tool or Lathe tool?

[itsme_Bernie]

Maybe I'm missing something but I see now way for that free-swinging hinged screw to lock/hold an HSS cutter... it just flops in the breeze.

Exactly!

 

[DavieJ75]

Gonna say shaper tool. The bolt and head is to lock a bit and will work when it is indexed at an angle. You can see the angle points and the pin for making sure you have the bit in the correct angle. If you look at shaper bit holders they have a very similar design and exact operation. This one is unique in the way it is holding the cutting bit. I have a Williams style tool holder for my shaper and it has a similar idea of angle of the cutter.

 

[pontiac428]

These are tool holders... but they make sense.
I am still going with the Johnny Cochrane defense- it does not make sense, therefore you must acquit.

 

[m1kemex]

Some kind of vertical bit holder? Those were marketed as "diamond" holders.