Judging by your vid, your shade might not be the E30 one. Might be the angle, but it seems to be too large imho. The mechanic seems different too.
In general, it can be stated that 2 different versions of the electric sun blind were offered. The older one w the center guide (which I own too for example) and the newer one shown in the link I posted.
Both versions are rather crude constructions by nowadays standards, designed as retrofits and come w flocked boxes to mount on the rear window shelves. The original wiring which came w these sets wasn't really more than a pair of speaker wires, 2 pins to attach it to the cigarette lighter and a switch. At least the first version wasn't even BMW exclusive, it was used in older Mercedes as well.
So the style of your sunshade certainly fits to the late E30 era, but it's imho not 100% clear if it's really an E30 one.