[mastek]

I think I understand now why GC wants you to send the kit back to them.
From what I can see in the pics, you are missing the sway bar links and bump stops. And I vaguely remember something about a rear shock mount.
But there are a lot of small pieces (proper size washers, nuts, etc) that make this kit complete and prevent noises.
For example, I noticed that the part of the strut clamp that will have the sway link attached might need certain washers and or different stepped inserts, as that fitment has to be on.

Honestly, I understand your frustration... you bought a used kit to save some money and it came incomplete. This would be easy if this kit was not so complex. Now your in a situation where you have to spend more money to make this right... and possibly more then if you ordered the kit new from a dealer or GC.
Sorry I could not be more help. But I highly recommend sending the kit back to GC or taking detailed pics with visible measurements of each piece and email them to GC and have them send you replacement pieces even for pieces that you already have if they are unsure about something.

From what I remember, this kit went through a little bit of an evolution and different parts were used over time by GC to improve this kit with albeit small parts like washers, nuts, etc.
So i think the issue for GC is that it will take more time for them to figure out what your missing through pictures, emails and phone calls ... and they might even get it wrong due to the multiple parts used over time.... then if you just send them the kit to them and they can make it complete and proper.