This bit belonged to my great grandfather, I assume it is a screwdriver bit for use in a brace. It's made by Marples and the end appears to have been hammered at some point (I think it may have been "repurposed" at some stage in its life!). Was this bit designed for use in an older type brace (given that the shank is a tapered and square in cross section), rather than the more conventional 2 or 3 jaw brace I'm familiar with? Any info appreciated.