63 Polara 500 questions

[Jim Altemose <jaltemoose@xxxxxxxxx>]

Thanks to all for previous answers.

As I peel the layers of my recently acquired 63 Polara 500 onion (I
like onions), I find interesting things and questions.

1. It's a push-button auto.  There's a pedal on the floor way up
underneath by the dimmer switch.  It has a small round pad.  You might
think it's the e-brake release, but it's not.  What is it?  Any tips
on how to use it?

2. It's a very original 79,000 mile car.  In the trunk is a gray
cardboard liner along the fender walls and underneath the typical gray
vinyl mat.  I'd never seen this before, but it certainly appears
purposely form fitting and original.  I'm guessing it's typically long
trashed by moisture and what-not and discarded.  Any insight or
history on this?

3. In an engine this old with no rebuild, what's the best gas to use?
I've put in Premium.  Should I be using lead additives to help the
valve seats, or something like that?

4. Rear end seems a little saggy.  Is there a way to check the correct
height?  I saw previous emails about this.  Can the springs be re-bent
or should they be replaced after a certain number of miles or years?

As always, thanks.

- Jim
Jim Altemose, Long Island, NY
'63 Polara 500 (Max Wedge)
'63 Polara 500 (383)
'65 Belvedere I (Street Wedge)
'71 Bronco