Okay, first of all, that is a gorgeous tool, kwigs!

Wood, steel, brass - what's not to love?
If I am understanding correctly, it's for close-quarter work, where there is no space to swing a shank left or right about the head of the unit being turned. Like close-quarter ratchets where you twist the shank or a knob on the end. That is, twisting the knurled shaft doesn't turn the whole head in the same axis as the shaft, it turns the screwdriver blade in a different axis. That means some kind of knuckle joint or beveled gears to actuate.
While I can understand why you might not want to take it apart, I would love to see the innards if you're up for it. I see a couple screws.
