A replacement mirror would be easier IMO, MikesMontes.com would be my first choice, he may even have one in your color…
Here’s a link to a similar mirror, with decent close-ups of the cable control.https://www.ss396.com/el-camino/MK-...VpNOo0oaqHqQQxawB6p-sr5VtxRoC58sQAvD_BwE
Note: there are 3 cables in this assembly, but not visible in 1st pic.
Points of failure usually are the cable control assembly, and potentially the base behind the mirror itself, if one of the cables snapped it’s most likely not repairable
As a temporary redneck repair:
Option1: roll duct tape inside out, fold it and tuck it to hold the mirror in a usable angle.
Option 2: wooden clothespin, take it apart, make extra notches on inside of ‘legs’ and push into place on opposite sides, cut leftover w wire cutters, use a black sharpie to color the wood. Make notches slightly less than the thickness of the mirror, snug is better.