Looking to replace the trim along the tops of the doors and the rear quarters just below the windows on my '72 Supreme. What is the exact name and does anyone have a source?

 

its the B85 trim option, there are no NOS ones, I have been looking for years, they are aluminum and anodized, there are a few places that will restore them, you have to take off the door cards and rears, to get access to the screws, and at that time the window fuzzies can be replaced as they are attached on prongs from the trim

 

Commonly called beltline moulding. Restoration of what you have as noted is your only option. If you find an NOS piece you'll find out what sticker shock is.