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The handle would be manufactured out of two pieces of formed sheet silver and filled with a setting compound to which the steel hook was inserted. At that size, the amount of silver required to make the handle would fall under the weight requirements for compulsory hallmarking.
If you ever come across a similar article that is hallmarked and wondered why, then this would have been submitted voluntarily by the maker, and often was, and an aid to marketing.
Your item may well have part of a set with some of the other items hallmarked.