I really dunno
It is my neighbor's plant so I go by what she tells me. She is 85 and sharp as a tack and the only person that's ever lived there. She had the plant put in and the plant has been there over 20 years. Could the spines be dark from age?
I'm inclined to agree it isn't a Golden Barrel the more I look at what's in a variety of plant files BUT Eriosyce looks more likely. If it is an Eriosyce it may be a hybrid of some sort. I'll post a few more pics here for you guys and maybe you can get a better idea and I.D. it more accurately. Maybe all of these photos will help?
If you want more pictures I can get some close up specifically of the spines for you. I just have to walk next door.
Whatever it is though, it is a really nice specimen and a very pretty plant.
