Because there is no known maker for these, you cannot assume they are any particular artist or tribe. Therefore if you’re selling them, you should simply call them Southwest style, or something like that. I highly suspect they’re fake/imitation, and we have had many discussions on here regarding this type of jewelry with block letter hallmarks that can’t be attributed to anyone. The fact that there are some similar items online on eBay or Etsy with the same hallmark does not prove they are Native made. If you had provenance from the actual artist or a legitimate well-respected store, that would be different.
You might want to read a recent thread regarding this particular issue. Kirk Smith?