I'm not familiar with a specific reference to 宣城伦敦金 which seems to be a mix of Chinese characters and a reference to London gold, possibly implying a connection between Xuancheng, a city in Anhui Province, China, and London gold, which could refer to gold trading or a gold standard associated with London、

Could you provide more context or clarify what you're referring to? Are you asking about:

1、Gold trading or gold standards related to London and Xuancheng?
2、The history of gold in Xuancheng or its significance?
3、Something else entirely?

Without more specific information, it's challenging to provide a detailed response、However, I can offer general information on gold trading, standards, or the historical significance of gold in regions like Xuancheng if that's helpful.