They are a factory item for the 53-56 ford trucks.
The one in the auction is a repro. I sold an original bird to a fellow who made the mold and he produced these.
I had the bird for about 10 years and had been replated and some of the fine details have been lost so the repro is no where near what the original ones were.
I sold my USED one for $501.00 on ebay and I Knew where a NOS one was so I upgraded to to the NOS one and it only cost $500.00 LOL
I never installed mine and its in my sock drawer!
Kevin S in Akron, Ohio