I picked this up as part of a " Sweeten the pot" deal.
I like the blade , but never have seen that style with a wood handle.
The shaft goes through to the end of the handle.
Not sure if the ferrule got messed up or it's supposed to be that shape.
Any input as to age?
I can't find a mark anywhere except possibly a 4.

Good lookin' driver! Ferrule looks like it was made that way.

I remember my grandfather having a screwdriver handled like this, with the metal running all the way through.  I may still have it somewhere.  It was in a early '50s metal tool box.

A thru bolster screwdriver is the sign of a top notch driver. Whia still makes a thru bolster with striking cap driver and they are my main line screwdrivers. Even the much ballyhooed and grossly overpriced snap-on hard handles are not thru bolster.
Some of the bigger ones even have a hex at the bottom of the handle for use with a wrench.