Koreans in China all fled to China after the Tang Dynasty. War, natural disasters, man-made disasters. . I guess all those things are lost.
Only by going to North Korea or South Korea to find relatives can you get the genealogy. . But ... Now people from two countries.
People are not old. . . If you really can't find it, don't force it. . Because it is estimated that the names of your husband's father and grandfather are not arranged by generation.