http://www.billionsandtrillionsinc.com/pics/mirrors.htm This website has a lot of NOS GM chrome parts. Don't know if you have already looked here. Happy Hunting!!!!!
I see you are looking for NOS for this project but if you need a really nice used one, for a different project, I have one, pictures on about the 4th page, I would like to trade for a like manual driver side mirror. I bought a passenger side base from someone on this board and thought I had the top. Now I am looking. I can send you more pictures if there is any interest. Dean
Still looking. If someone has one they do not want to sell perhaps you have need of some hard to find parts and are interested in a trade. If you have one and would consider a trade pm me with what you need.