Fuel cap on 98+

[Astro4x4]

Anybody had thier fuel cap apart and put back together. I pulled mine apart to polish the cover and lock cover flap and now have an extra part I can't figure out where to put.
Or maybe someone has one off they could take some pics of the underside for me?

[squiggy]

There not that many separable parts to the cap. I haven't even found the rubber gasket listed separately for the cap.

What extra part do you have?

[Astro4x4]

This is the part in question - the rectangular piece with the tabs on it. I'm sure it's part of the lock flap assembly but where the hey does it go?