Tool kit question

[Rebar]

Hi,
I picked up this tool kit off ebay for a good price, it was being sold as a 944 kit which obviously it is not. I am wondering 3 things?

1. Anyone know what year it is from?
2. I seem to the only thing missing whatever attaches to the spark plug socket with the spring, is it an allen wrench that goes in it? If so what size or does anyone have the correct piece for sale?
3. What are the 2 pieces on the far right, it appears like it is a double socket and the other piece is just a straight bar, I would think they go together but there is no whole in the socket for the bar to go in. What is it for?

ps- the toe hook is the only tool that came with my car 1977 911s, as you can see it is not quite as shiny as the rest of the tools.