I think No1 is a salesman's model of a safety coupling for use on coal tubs down mines, rather than a full sized item.
See This Link.
http://www.bbc.co.uk/ahistoryoftheworld/objects/4gKYyof5RWyqR7zgBLmv9w
I started a quick search based on the idea that part of it looked similar to a wire rope clamp used for tensioning old telephone aerial cables or dropwires, and bingo.
Even though it pre-dates WW1, it didn't stop my Dad getting a crushed finger between two tubs when he was down the mines in WW2
Bill
p.s. looks like I've been pipped at the post. I was replying to an earlier end of the thread and only found the later replies when I replied myself. 
Edited By peak4 on 23/06/2019 23:35:00