I dont' know if any of this will help, hopefully someone will give you a definitive answer. Maybe some of the links will lead to something you can use.
I'm thinking you know that if your shifters are exactly like picture 1, they aren't the same as picture 2. The difference being the right shifter in picture 2 has a little micro adjuster for the RD indexing (parts RE 005 and RE006 in the picture 2 diagram. I have that kind of shifter and it's officially called "8 Speed Syncro", and sometimes called Syncro 3 (which I will call them from now on!) as opposed to Syncro 2 which doesn't have the adjuster. I believe Syncro 2 was 7 speed (with changeable inserts for 6 speeds), and Syncro "3" was 8 speed. I've read that the Syncro 2 could be modified to 8 speeds too. - if your shifter is like picture 1, and is 8 speed, it was possibly modified from 7 to 8.
It's confusing, but picture 1 are different than mine/picture 2 regardless of what they're called and therefore the exploded diagram in picture 2 is for Syncro 3 does not apply to the Syncro 2 shifters in picture 1.
I think that picture 1 and picture 3 are both Syncro 2 the difference being picture 1 is higher end (C Record?) while picture 3 is Athena.
VeloBase.com - Component Listing
I think that picture 3 might apply. I think it's also a Syncro 2 shifter, but Athena rather than the higher end one shown in picture 1. I'm not sure if all the parts are there. Check out Velobase above.
You might want to definitively identify your shifters as being Syncro 2 or 3, and if "2" (i.e. picture 1), find an actual exploded diagram for them (see disrailigears link below). If you decide they are Syncro 3, the exploded diagram you have in picture 2 is accurate for them.
I think this might be a more accurate diagram of Syncro 2 shifters, note the washers:
Campagnolo - Syncro (February 1988 version) scan 3 (disraeligears.co.uk)
That disraeligears site also has diagrams of the original Syncro ("scan 2" on that site). The original (called Syncro or Syncro 1) were also 6 or 7 speed like Syncro 2, but had a little secondary lever on the right/rear shifter.
In other words, all three versions are easy to distinguish because they have different external features and it should be straight forward to find an actual parts diagram for yours.
If your shifters are Syncro 3, like the ones in picture 2 (like mine), I can try to take a look and see if I can see the washer without disassembling.
The Tears for Gears site has a lot of good info on the Syncro shifters. Check it out and read comments for additional links that might help, and searching for various syncro search terms might get you the info you need too. I went through this several years ago when I was figuring out exactly what I had (Syncro "3") and like I said, confusing, but interesting!
Campagnolo Syncro II shifters ~ tears for gears
Syncro Tips and Tricks ~ tears for gears