3 Probably Dumb Questions....

[THE "10" SILVERADO]

Alright, I have a 77 Silverado that I got about 2 months ago...just about the only thing I have been able to do with it was take off the glide out spare tire rack....I have a few interior questions that I would like to ask before I start ripping out the brown everything and putting in black. The first is right under the door panel there is a carpet section that is right above the bottom of the door....while looking at new door panels I have yet to see anything that would be under it (1st two pictures)....what is under it because I might want to get a new one for the new black carpet...Also my cab has no headliner (next two pics) can you tell me if it is fitted for a headliner? Because I want to get new black ones and LMC has ones for trucks that weren't fitted originally and for those that were....I don't know if mine was....and last but not least what is the black protector thing behind the seat? (last pic)...It seems like it is really worn out so I'd like to replace it but I do not know what it is called to find the part out....