Yes
1970-72 Dart, except the side marker light is in a different location on the 72
A few extra bells and whistles with the interior, hubcaps, & body trim , but no performace parts
Try placing an ad on eBay or craigslist.com
either the junkyard or see if a parts store can get it for you.
It all depended on what engine was in the dart, there were 2 differen't trannies.
Yes
get a chiltons repair manual at the library for your car.
Yes
2 horns.
5*4.5
go to manheimgold.com and figure it out.