It must be the season for broken side mirrors! I am also replacing the mirror in my sideview ('72 2002tii). I was able to get a replacement mirror cut and I have the spring. I believe all I'm missing is the gasket? I was wondering if someone would be willing to check my work. Thanks in advance!
https://www.rogerstii.com/bmw-3-0cs-2002-trapezoidal-mirror-frame/