Identifying halmark details

Hello, I wanted to know more details on a hallmark symbol present in one of the silver item i posses. Sharing the images of the item and the mark. Needed details on who manufactured it, what year was it hallmarked and from which assaying agency. Any help would be appreciated. Thanks

Maker/sponsor, R&B, is Roberts & Belk of Sheffield. Hallmark is Sheffield 1911 (date letter t). Garrards would have been the retailer.