Yes, i would agree with Jean that the dress is rather low end and recent Madura dress. This is the kind of dress most often found on replica keris sold in import stores around the world and probably in local markets for tourist. However, those usually have cast iron blades, not wood.
Since this was kept as a treasured item i am inclined to lean toward Leif's suggestion that this object may have been a theatre prop that perhaps belonged to someone in the family of this person you received it from, but i wouldn't place that dress older than the 1960s or 70s. Of course the "blade" could be older than that, i suppose, but suspect this object isn't quite as old as you think it might be. It would not seem all that unusual to consider such an object to be a family pusaka if your grandfather (or grandmother) was an accomplished dancer or deep into wayang and had passed this down to the father and then the son.
