I’m fascinated by this. On the one hand, I agree with @neonknight-- there had to be more than the aged son behind the company’s production process. And it would be nice if the cartridges were once again available. I cannot even begin to speculate who would have been involved, and whether their role in producing components was still subject to the family’s quality control. I did have one stone body re-done by Koetsu a few years before Sugano the younger passed and the turn-around was precisely eight weeks, which I thought was impressive. I suspect the family still retains the brand name, though, which would make it difficult to market under the original name, and possibly, under the model names.
Call me an interested spectator with a vested interest as a consumer.
PS: It appears that this new enterprise has filed in the US for Koetsu for phono cartridges. You can do a free lookup at the USPTO. No legal advice or opinion intended.