These have been around on the commercail market in the US for about ten years. They are not all that common but normally sell in the $125-150 range. I had a few several years ago that appeared to have been issued. They were in US M8A1 scabbards with metal tips and had numbers hand etched on the blade with an electric pencil.
I have a book, I think the title is "The World's Armys" that has a photo of Belgian paratrooppers on parade with FNCs that have this bayonet mounted on them.