Hey Lee, I would say your DX patch is original and NOS. When looking to buy NOS patches it’s always a good idea to see a photo of the back. If it has a shiny backing that usually indicates a newer (heat sealed/iron on patch). There is a thread on Oldgas that most of us patch collectors post on when we get new ones added to our collection. I have posted the link to that thread below. There are a ton of them in there that you can use as a reference. I have also shared a photo of my DX Diamond patches as well. Happy hunting!
-Mark
https://www.oldgas.com/forum/ubbthreads.php?ubb=showflat&Number=340730#Post340730
