I mean, if I go to a priest who was ordained BY SSPX BISHOP before 2023, may I be sure he is validly ordained?
That there were valid oils? I dont talk about NOM priests who came to SSPX, but I talk about priests prepared and ordained by SSPX bishops before 2023. I hope I explained it better now.
Using invalidly consecrated oils does not invalidate an ordination. It definitely renders it sacrilegious and, I guess, it may render sacrilegious all Masses celebrated by the validly ordained new priest with non-consecrated hands. Somebody else correct me if I'm wrong in this last point.
Invalidly consecrated oils would invalidate the sacrament of confirmation and extreme unction, but NOT ordinations.
EDIT: If you are concerned about one particular priest, ask him directly the details about his ordination. If he refuses to answer, ask his superior. If he refuses to answer, ask Cathinfo. In any case, pray.