Gas Gauge Inner Nut

[Bill in SoCal]

Thanks for the information on inner nut removal, but I am more interested in the inner nut than how to remove it. The inner nut is a six point not and eight point nut. The standard tools (as you can see in some of the pictures) remove an eight point nut. The lens in the middle is smaller and does not appear to have a face plate behind it. I looked in the judging standards and did not find it mentioned.

Can someone help identify the inner nut? Bill