Reading from top to down, right to left:

萬曆四十六年戶部進到大興縣鋪戶嚴洪等買完

萬曆四十六年 is the 46th year (1618 A.D.) of the Emperor Wanli's era name. 戶部 was the ministry responsible for monetary affairs in Imperial China. 進到 is some kind of verb that roughly means "presented as tribute". 大興縣 is a county name, the name of which still remains as a modern day Beijing suburb. 鋪戶 means "shop". 嚴洪 is a person's full name. 等 is similar to "etc." or "et al.". 買完 indicates this was purchased by the aforementioned person and their companions.

So the roughly summarized statement is "paid/donated by merchants Yan Hong et al. in Daxing county, presented by the Ministry of Revenue in year 46 of Wanli." The markings serves as a certification or proof that this person had paid tribute to the imperial court in that year.

Source came from these two articles: first, and second. Ctrl+F the simplified form "万历四十六年户部进到大兴县铺户严洪等买完" and you can locate the relevant paragraphs and feed them into a translator for further reading. Seems like these ingots were buried in Dingling which was where Emperor Wanli was buried. It was the only Ming imperial tomb to have been excavated.

__

From a Reddit Post from June 14, 2022: