First time I've ever seen these on ebay.....not mine....given the amount of stuff he has listed it looks like another one is gone....
https://www.ebay.com/itm/1957-Ford-Ranchero-Interior-Rear-Lower-Trim-Pieces-Pair-LH-RH/264921512453?hash=item3dae8d7a05:g:--AAAOSw5udfn035
These Lower "B" Pillar Trim pieces are extremely hard to find, as Bill will tell you. And when you find them they are usually rotten on the bottom.
John