You have a very old gunong, most probably 19th century. What are the hints for this assumption? The elongated handle is typical for older gunongs IMHO. The casted ferrule in one piece with the guard is another hint. Also the blade form let me think like this.
The advice from Ian seems to be a good one but I would try to loosen the hilt and refit it properly.
Compare with three similar examples from my own collection.
Let us see what you will do with it!
Regards,
Detlef