Billet wheel adapters

I have used spacers on three of my cars, steel spacers I made, billet spacers I made, and 1 1/2" billet adapters that I converted to spacers, that I bought. But all of them also used quality three inch long 1/2" studs. Adapters are a completely different animal.
Best you can do in your situation is new 7/16 studs and billet adapters, and you are doing that. Carry on .
Ps: I don't think I would feel right selling used cast adapters to anyone.