Identifying maker

Hello
Please can anyone help identify the makers mark and hallmarks on this lovely little locket please any help will be greatly appreciated thank you in advance



The hallmark is a London import mark with the date letter B for 1976. I cannot work out what the first letter of the importer’s mark is (possibly G?) but I can see a C as the second letter. In any case it is not one which I have seen before so I am unable to identify it.

Phil

Thank you for the information