Dura Ace SL-7400 shifters - what?

I have what I thought were 7-speed Dura Ace downtube shifters (and the corresponding rear mech).

I've managed to track down an assembly diagram, which looks like this:

BUT

the parts I have look like this (sorry for crappy photo):

Similar to what's listed on eBay as a "6-speed" set of shifters (below).

So I ask:

1. Do I have 7 or 6 speed shifters, and how does one tell?
   
2. Might I have
   a 6-speed mech and how would I know?
   
3. How the hell do I assemble the
   parts I have?
   
   

Thanks, wise people.