Yep, that looks familiar, i replaced my original hilux mirrors about a year ago, with Chinese copies. . . After glueing the old ones together a few times. 20 years of hot sun made them brittle. But. . The copies are s**t. One year on and the mirror backing is peeling, they shake& vibrate, and they could be bigger, so I was very interested when I saw what you did!
The black plug is for the wiring for electric mirrors which sr5's had i think