I have literally dozens of them from CRH searches. There are also a lot with Kennedy stamped on them.
My point is that while it is probably from the 1970's, there's really no way to know when it was done. However, there is documentation of when these state counter stamps were produced. And the 70's is likely. It's like when you find something 200 years old metal detecting, but it was only lost a few years ago. (You can usually tell age by depth.)
I never said the coin was counter stamped in 1974. I said it’s dated 1974 with the state of Louisiana counter stamp. In the 1970’s and 1970’s making coins like this was very popular. If it was counter stamped 5 years ago it would be a better stamp than this one is.