Need Help Identifying Chinese Export Hallmark

[SterlingRookie]

Hello, as the title states, I found this small silver cup. It has been tested and is silver. From checking the markings on this website, I am inclined to think Cumshing, but the other square hallmark has me confused. Any insight would be greatly appreciated!

[shikiamondo]

Hello there,

The mark resembles 'SF', which stands for 'SING FAT' (Canton and Shanghai c. 1880-1940)
and then there's a 'fineness' mark '90',
lastly the artisan mark '鴻祥', which could be pronounced as 'Hung Cheong' or 'Hong Xiang'

Hope that helps,
Connor