Duh! How could I have missed that?

ASARCO would be a perfect fit. They are already nearby at Mission-Pima, and bit north of there at Silver Bell, and well east of there at the Ray Mine, which is south of Superior. Also, JB has been a consultant for them at Silver Bell for many years, so he has had a working relationships with at least some levels of management.

Then, there is their Souther Copper division operating in Mexico and Peru. The Mexican properties are near LBSR claims in southern Arizona. All are basically copper mines, but with many other similarities as compared to what we should expect from Hay Mountain.

Souther Copper is also involved in a major exporation project in Chile, so their interests are not limited to existing mines.

FWIW