Rigmaster (Bret Luter) on the forum (do a search, I've posted his contact info a few times).
Ian Sherman @ NEO BMW Breakers -- http://www.neobmwbreakers.com.
Did the allen bolt/washer get pulled through the door sheet metal with the mirror? Is the wiring harness connector still intact (they're two male connectors joined with a dual female, kinda hard to explain)?
All E34/E32 mirrors should have wiring for heat; the glass contains a matrix; the original glass can be swapped to a new mirror body if it's still intact and the replacement mirror is of the same vintage/type as the original. E30 mirrors are different, although they look the same.
Another thing to remember is to get a memory or non memory mirror, depending on what's currently on the car. The harness will physically interchange, but I'm not certain if the servos will work without active input from the potentiometers were you to stick a memory mirror on a non-memory car.
Also, you do know that the mirrors fold in, yes?
best, whit