I have that same ratchet. What I did was take a vintage 1/4" extension, whack off the end to the appropriate length, dimple the middle of the extension "sides" with a cold chisel so it wouldn't push through and blue Loctite'd the 'lil bugger so it wouldn't fall out.
Oh...and I home machined the 4 sides (from the round profile) so it would just drag through the square opening with decent friction. Yes, I know it has a ball detent for holding it, but that ratchet itself reverses and the head shape allows it to be operational from either facing.
There...that's my story. No pictures, just theater of the mind.