I don't know about GM, but the "chrome" on my 47 Mercury was actually stainless steel. The man who bought it from me after I'd owned it for 13 years straightened all the little dings out of the trim and re-polished it like brand new. No plating involved at all!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!