Thanks KC and joe
KC,I was not sure,but I have done farm work,most of my life.I have used a few different type of stretchers,building and repairing fences.The way the piece hanging on the chain opens up looked as though it would grip the wire,while the prongs on the end would grip the post while pushing or pulling on the handle the clamp holding the wire would get tighter as more pressure was put on the handle.
Yea,joe I would think it would be tough to use,they have come a long way since then.
Anyone know about when these were made