Scottish Silver Hallmark I.D.

I have this 13 piece, what I believe is a Scottish Sterling silver tea spoon set, but I have not been able to find the hallmarks listed, it came with a card inside: James John Brown, Lerwick, Shetland. Can any one help with I.D. of this mark,
scottish silver tea spoon set.jpg

This is a silver plate mark of Francis Howard of Sheffield and dates to c1875.