Dash PANEL HELP 1966 Cuda.

I have problems with my fuel gauge not working and removed my panel to find that it appears I am missing a piece connecting my panel to the gauge. What it this called? One pic is a panel with one and the other is mine without it.

2nd on my steering colum there are purple or violet wires in a breaker/fuse box? One wore is not plugged into anything and I can't find where it goes.

3rd where is the voltage limiter located on a 66 Cuda?

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