I have just been given a silver sauce boat by my mother and have dated it to 1972 but I am unable to ascertain the maker. It apperars to say j.j.c but the middle j is quite feint.
Possibly John J Cooke Ltd, manufacturing jewellers and silversmiths. Address is 14 Fownes Street Upper, Temple Street, Dublin 2.
Tel: 01 6771756. Apparently based in Temple Bar since 1952 but not sure if in existence prior to that.
Just to confirm Scorpio's findings, I contacted a friend who is a silversmith in Dublin, and was working in the trade around this time, and he came up with the same name, John J Cooke.