From 1922:
Take 4 red herrings, ½ lb. butter, 3 eggs. Pour boiling water over the fish and allow to stand 20 minutes. Take out all the bones and, after removing the skin, put through a mincer. Place a basin with the ½ lb. of butter in a saucepan of boiling water. Allow the butter to melt, then put in the fish and the eggs, well beaten. Stir until it thickens (about 5 or 7 minutes), then put into small jars and seal down. This may be applied to any dry fish, and is nice and tasty for lunches or sandwiches, and will keep for months.