These came out of an Iowa barn.  Thought maybe they were a rope tightener for corn or oat shocks.  Maybe for hay?  Looks like there is a pulley wheel for a rope, and the finger ends can be locked into place.  Any ideas for sure what they are?

No idea,  but lots of barns have hay lofts, and had (maybe still have??) rope/wire pulley systems for getting the hay from the cart to the hayloft - maybe this is an area to check out...

I think you are correct.  It looks like a longer, fancier version of a corn shocker for tightening rope or wire around the shocks.

  Hay sling latch