Hallmark Help / sp or silver tray

[kirbz]

This hallmark is rather worn and hard for me to decipher. The tray is 15.5" diameter and has been monogrammed in the center. Thank you.

[Bartholomew]

How to tell silver plated from sterling silver? p2: FAQs + Q&A Forum

https://www.ebay.com/itm/255883654936