E-body side mirror restoration

Does anyone have experience fixing the common "floppy mirrors" on E-body doors?

I can only guess that you're talking about passenger side mirrors. I fixed the one on my 71 Challenger by soaking the mirror in laquer thinner till the glue holding the mirror glass on turned loose. I then took it apart and drilled out and tapped the places in the back that hold the plate tight against the ball that the mirror rotates on to adjust. The plate is originally bradded(sp?) on and one side turns loose and lets the mirror flop. If you have a painted mirror instead of chrome,it may be cheaper to bust the glass out and replace it than to soak the mirror and eat the paint off.It's easy to figure out how to fix after you get it apart. Good luck.