Retrofit S-Type Autodim Mirror

I miss the Autodim mirror I've had on previous cars. I've recently found a taped up connector attached to the wiring loom to the overhead console. Only found it by chance as it's well hidden and the loom has little free-play. As my S-Type is a late '57 I'm guessing this may be the pre-wiring for either a sunroof or the Autodim function. I appreciate the mirror fitments are different but does anyone  have any knowledge about the wiring and if the screen has to be replaced ? I did read somewhere of a guy who had succeeded in fixing the new mirror and blanking off the wiring but I've also read removing the std mirror fitment  is fraught with danger of cracking the screen.

I dont really need the rain-sensing function so would the Auto-dim function still work with this feature being redundant ? Any help really appreciated.