1972 side mirrors

OK. Thought I did the hard part when I fabricated a new backing plate for my drivers side mirror and fished it into place through the door handle opening. However now I can't seem to get the mirror to mount on the mounting bracket- The one that screws to the door with the "loop" on it that the tapered mirror mounting bolt passes through. Is there some secret to accomplishing this??

I had the same issue on my '75 -- a few times. It is hard to get it aligned. One time I ground down (I forget exactly where) so it would fit. Another time it finally went in (I think it took a few special words to accomplish it). Some seem to go together easily, others just don't fit, even they look exactly alike. Good luck!

There is a metal panel between the interior and the door skin where the mirror mounts so you can't get to it that way. That's why I had to "fish" a new backing plate through the channel accessed by taking the door handle off. I thought that would be the hard part but I guess not. It is mounting the mirror to the base plates!

Thanks but this is the drivers side that is mounted via a backing plate installed at the factory. That's what was missing on my car and someone used well nuts as you described but over the years it became really loose so I wanted to reinstall a backing plate which I did. Now the screw that holds the mirror to the mounting plate doesn't line up or screw in!

My '73 driver side mirror was mounted with Well nuts as was the passenger side that I put on later.