Im guessing B.S. (but I'm no expert), but I have owned quite a few prems & others with twin h/l fronts, & stripped out dozens over the years.
I have some(new) aftermarket ones that I bought around 2001-2, & they are noticeably thicker around the edge (rolled bead), & heavier& have a quite shiny chromed look.
I should be able to put my hands on them easily, & I will run a magnet over them tonite & let you know.

Cheers
Max