Australia Antarctic KGV1 Robes cover registered Heard Island. Extraordinary item

The high value Australian Robes stamps are very scarce on cover. Although this item is philatelic, no similar covers would exist, especially registered at Heard Island. This Australian Antarctic base was started in 1947 which is the year this cover was sent. It is an exceptional item from the earliest days of the settlement. Sent with Standard Delivery - Registered.