Help finding date and city marks.

I have two silver brooches both bearing the same hallmarks. We have identified the maker as “jewellery and metal manufacturing company of Ireland” but the assay mark cannot be found anywhere. It looks as though it is a circle with a line through both horizontally and vertically. See photos. The date letter is a capital R. Can anyone shed some light please??

Sorry for the lack of photo. Cant seem to upload from my phone.

Keep trying, pictures are essential for identification.