Disc brake wheel studs

If your using the one piece rotor, big bolt pattern, Left hand studs never existed for those things, so you aren't never going to find any.
The end of the lefties, was 1970, and the original rotors were two piece. Rotor, and hub, that the wheel studs, (lugs) held them both together.
Two piece rotors, and the single piece, were two different animals, so the studs were different.