I just removed a set of these:
http://www.blainefabrication.com/ductplenums.html
from my race car.
They are like new, with hardware as shown. Alan Blaine suggests new bolts which can be readily obtained from him for $20. My bolts look good except for a little bit of rust on the bolt heads, barely noticeable.
These sell new for $250, I am asking $150 plus shipping. Located in North Central Florida for local pickup.
Photos can be emailed, but they look just like the picture on Alan's website.
bock