I think you are mistaking on the material of those moldings. Maybe double check and look at them close. Maybe they are the 67 stainless moldings?
All the original 68-72 cars I've seen are aluminum. But I have heard that early 68 cars got stainless in some cases.
Any long term 68-72 Dart owners hears to verify aluminum wheel lip moldings??
Here's an NOS 68-72 aluminum wheel molding. Look at the picture enlarged. You can see that is aluminum from the way it shines, texture, and thickness. P/n 2785856 for passenger front.
http://www.ebay.com/itm/NOS-Mopar-1...Parts_Accessories&hash=item339b64fef4&vxp=mtr
Here's NOS rears:
http://www.ebay.com/itm/NOS-Mopar-1...Parts_Accessories&hash=item339b64f33e&vxp=mtr
Here's a old for sale ad that shows up close picture that you can see that the molding are aluminum not stainless. Seller incorrectly had listed them as stainless. http://www.forabodiesonly.com/mopar/showthread.php?t=155027