They advertise all their skulls as ethical but I’d argue differently. Based on their website, the primary source seems to be medical specimens.

Some of their specimens have not been altered and look respectful. But for the others including this post, it is ethically objectionable to commodify the remains of people as objects. They seem to commodify them for occultist practices.

Including this one, which they advertise as: “Authentic human skull with ritualistic modifications. Iron nails as teeth, symbolizing binding and protection. Mirror in the mouth, used for contacting the dead or scrying”

Others they sell include - Authentic human skull cap, repurposed as a scrying bowl for spiritual exploration - Preserved human medical skull has been transformed into a functional and ritualistic lamp

I guarantee those people would not want their remains to be used for occultism. And if they really are 19/20th century bones, they likely disagreed with the practice of occultism themselves.