What are you talking about?
The UH-1 first flew in 1956 and the first HU-1A (they were called HU-1A before they were changed to UH-1A) saw service in 1959.
So please explain to me how the Huey did not exist in 1961? They did not arrive in Vietnam until 1962, but the Huey existed.
So please explain to me how it did not exist.
After that give me some reasons why the Huey which did more for the Vietnam war than any other helicopter can not be considered the best.