I believe gsfred still has an NOS mirror.................http://www.v8buick.com/index.php?threads/nos-65-67-lh-remote-mirror.338871/
I have a nice complete used one, as I remember no pits and chrome nice for used, will dig it out and inspect, and post back.
Found it, It is complete, no pits but some crazing on chrome, chrome is good other wise, the glass is not perfect but good. $150.00 plus the shipping. Can post pictures if you are interested. Thanks Bill.