Many thanks for the contributions, they are very welcome, especially the Esther Forbes mark image, that I can't recall having seen before. Tom is currently in the process of updating the Encyclopedia and the images will be added soon.
Some background for those who may be interested in the mark of Esther Forbes, she continued the business of her deceased husband Robert Forbes (Quarter Brother 1701, Freeman 1715) who died in 1718. She entered three marks with the Dublin Assay Office. Work with her mark has been recorded up to 1729.