This is a lesson for all new to the world of Mopar and especially C-Bodies.
1. Buy a factory parts book
2. Learn to use it.
3. Bookmark every website that sells NOS parts.
4. Bookmark all he sites like PartsVoice that search other sites.
The parts book will tell you the factory part number for the parts in question. It will also tell you what else they are used on.
If you are lucky the part is also used on a popular car like a Road Runner or a Charger and it might be reproduced. It is unlikely that any C-Body specific part is being reproduced, there is just no money in it (not that there are not any).
I could go on but this should do for now.
Alan