Current auction shows a Falcon plenum and not a Mustang heater delete plenum like the description claims . The Mustang version has the hinge on the other side and consequently the door opens opposite of the one on auction.
https://www.ebay.com/itm/265009105859 .This is a relatively common part on a Falcon. It goes on the driver side on a Falcon.I included a picture of the page 17 of the body assemblyline manual which has a illustration of a proper Mustang heater delete plenum . You can see that the door opens on the opposite side .I just want the buyer to know what they are getting for what they are paying regardless of if a clone or a genuine car.