I plan to buy a circa 1950 native bolo tie with a turquose center piece with silver feather design holding the stone. There is no hallmark on the back or siver mark on the bsck. I was told many natives creating jewelry for themselves didn't initial the jewelry. Is that correct and legit?

Yes not all sign a hallmark and some only start signing after they get a little famous. But if you want to know the artist and know it is authentic you should go with one that has a hallmark.