Generanl Jacob served in India in the fifties of 19th century. He designed his own double barrel rifle and? long sword bayonet for it, with hilt protected by basket. Jacob died in 1958 and most of his bayonets seem to be manufactured between 1859 and 1861 by Swinburn&Son in England. Most guns and bayonets were probably sold on the Island but some had seen service in India. The bayonet has distinctive multi-fullered blade and scabbard (I don’t have it unfortunately) with characteristic throat. Some exaples have reduced basket.