This all corresponded to Butcher Hua's situation; he and his wife had no children, and Mrs. Su's blindness, as well as the origin of the scar on Butcher Hua's chin, were indeed as previously described by Butcher Hua.
We can essentially conclude that this Zheng Cheng is indeed Butcher Hua's nephew, as he claimed.
Even if he is not really his nephew, he must be a close family member, otherwise he would not know such private matters.
Anyway, at the time of Butcher Hua's death, it was already stated that all his belongings were either burned or buried with him, and the house was almost completely empty, containing only some worthless items such as tables, chairs, and benches. There was no reason for anyone to purposely deceive about such things.
Zhuang Jingye thought for a moment, then nodded, "Alright, you can come with me."