Mine came from Goodmark, and it is steel. But, as you can see in the screenshot of their website in my earlier post, it is for 70-74 Challengers. (Mine is a 70, and that steel part is exactly correct).
But now we know that Flores_57 has a Cuda, and I don't know what was on them, or if anyone repops it. I wish I could help you with that one! If you call Sherman and/or Goodmark, you should get an idea if it is available.
-Tom