Calling Card Holder ID

hi, can anyone tell me the date and makers name on this piece of silver

Many thanks in advance, this is my first time on this forum.
All the best

We need to see the hallmark on the other part of the case - this should be the full mark with town mark and date letter in addition to the duty mark, maker’s mark and lion passant which you have shown us. I would expect to see a Birmingham anchor as I believe that RT is most probably Robert Thornton.