Nice keris and I think it’s in original shape, no need to change the hilt.
The warangka is in Urang Urangan/Deng Udengan style, The hilt in Ukir Topi style (hat/cap)
The flying horse carved on the warangka called Mega Remeng, this is a legend about a flying horse owned by Jokotole, a king of Sumenep.
Now, it is not easy to find original keris like this even in Madura, Well…accept going door to door to collector houses. So…nice keris and just keep it, it is worth.