This item came from a box lot, the wood is very heavy, may be walnut or possibly south american.  The slots in both top and bottom are about two inches deep.  I'm unable to even make a guess.

It's used for aligning the frammis stator on a 1934 Light Four.

As good an idea as I have come up with in the last few days.

I thing Bill nailed it.

First thing I thought of was a knife switch.  Maybe home brew?  For a low voltage home power unit back in the day.   Just needs a brass bar to connect the 2 slotted pieces, holes are already there.   Slots in the wood, no idea.