Rock Auto Maybe? I'd buy a new switch if this is it...
Brad
Edit - nevermind, it probably doesn't come with what you need
Tomorrow, I am going to call a few of the parts vendors, Classic Truck Parts, Chev's of the 40's etc and ask them if they would check to see if one for a 47-53 or up to a 59 will screw into the 64-66 headlight switch and if it will, and the 64-66 headlight knob/rod will fit into that, then I will buy a new one.
If not, I will be calling Tom Myers in Miami, Oklahoma and see if he can come up with one. I don't understand why there are bezel nuts made for years all around 64-66 and not for those years.
This has been a problem for years because I've seen post on other sites from back in 2009 where people were asking the same question.
Kevin