Car Maintenence Help

I have a 73' Plymouth Satelite and i have some problems with it. One: i need to fix the carburetor because my fuel mixture is too rich. Two: I need to fix my doors because the passenger side can't open from the outside and I can't turn the key to unlock the doors. Three: I need new mirrors because the ones it came with were aftermarket and plastic, they were broken when I got the car. Four: I have to really press down on the brakes so I think I have to bleed them out, though my dad thinks that I should buy new brake lines and start from scratch. Five: I need a new gas gauge because the one it came with is cracked right down the center and it won't work (It already died on me once). Six: The biggest problem that I have is that every junkyard that i have called doesn't have a 73' satelite and I would like to know if there are any other cars that I can take parts from that are compatable with mine. I would greatly appreciate any help you guys and girls (if there are any) can give me.