Not super rare? I've had 40 e bodies in 35 years, been to a gajillion shows and have seen one in a car. That car just left my shop for France a week ago.
Very true, not much use for defroster in the south...
Funny, but the Classic Industries ad on the home page actually is showing a pic of this part... I checked and it doesn't say out of stock. Now might be the time to pick one up.