My guesses for artist are KRS-ONE and The Velvet Underground. According to the RIAA database - https://www.riaa.com/gold-platinum/ - KRS has never even gone Gold. I don't know how accurate that is. I would think one of I Got Next might have gone at least Gold, but it isn't in their database. Was that album before Soundscan?

I would have thought The Velvet Underground and Nico would have been at least Gold as well, but apparently, according to Wikipedia, it's only been at least Gold in Italy and England.

Interesting.

EDIT: Wikipedia says that I Got Next went Gold. My bad.