Since I may be the only person who has ever peeled off the black plastic coating on those brake shoes I'll report that unlike the chrome engraved ones, the ones I've seen are a hard Al alloy and of course don't have the engraving on them under the plastic. There may be steel ones with the plastic, but I haven't run into those. I much prefer the look of the older engraved type, much more elegant.
They polish up to a near chrome finish, here's one with the plastic removed after a few years of weathering:
http://picasaweb.google.com/
Kurt Sperry
Bellingham, Washington
USA