I don't know if this has been discussed already, I know they've been going on the 'bay for a while now....
Anyway, I got a pair yesterday, and they are beautiful, flawless, and truly NOS looking. Not to mention a bargain at forty bucks each, complete with trim rings. These will be used for my (hopefully) upcoming Bachbird project.
And if anyone's interested, they will NOT fit over the current black plastic Bird pups. I thought I might get lucky, as I have a pair of those sitting around, but I guess I'll be sending them off to Mr. Duncan for the guts.