Called "floor wiring covers"
I bought new ones and was able to find the original spot weld locations on my floor boards. Then I lined up the new ones to the original spot welds and tacked them in.

http://www.autometaldirect.com/images/6/442-2570-S_800.jpg

http://www.mattsclassicbowties.com/contents/en-us/p6397.html

Installed (but flipped up instead of flat on the floor):
http://www.cuda-challenger.com/cc/index.php?topic=97521.0