Hi bc,
I recently did some investigation on the markings. Despite the blurry resolution, it was enough for me to pick up a trail. Based on the info I have managed to compile "WH90" should be the initials of Wang Hing & Co, a company known for producing Chinese export silver. Founded in 1854 at Guangzhou (Canton), a flagship store was built in HK during the 1920s at Zetland House, 10 Queen’s Road, Central. The owner was Lo Hung Tong, and the store was known for making trophies and notable memorabilia for HK's various sports clubs and groups.
The Chinese characters you mentioned however, are unable to be clearly IDed due to the resolution (a better resolution picture will be much appreciated) It is known that silversmiths would have their name on a piece they made. I will likely need a clearer look to tell the name of the maker.
Attached here are some useful links that helped me:
https://www.koopman.art/artistdetail/233081/wang-hing
https://www.925-1000.com/chinex_04.html#M