Hi Conduit. In my opinion this is another nice old well formed keris blade, albeit with some significant material lose over the years. But it still seems rather solid and stable.
Some might call this hilt a buta form, some might call it a raksasa. There are other names i have also heard if we want to play the name game. It seems to have some age, but not nearly as much a the blade. It is a fair rendition of the form. Not extremely well carved, but not unacceptable. A nice and proper mendak between the hilt and blade would give this keris a better overall look and not really cost you too much. I am afraid that having a new sheath made for it would be a bit more of an expense.
I have some ideas about the origin of your keris, but i won't say too much at this point. Certainly Javanese. The hilt form is a Cirebon style i believe (though made later than that period), but i'm not sure the blade can be tagged to the same origin. Tangguh is certainly not my strong point, especially when judging just from photographs. Though i have some ideas about it i think i would rather leave it up to some wiser and more skilled folks to take a crack at first. Then i can either privately congratulate myself for being smarter than i thought i was or simply avoid the embarrassment if i was completely wrong. LOL!
All in all, a nice collectable old keris, though an incomplete ensemble.
