Hello Johan,
Processed woods are often not easy to identify, especially since often burl woods or stunted growth were selected by the carvers for their special features. So take my opinion with a lump of salt...
The hilt would very likely referred to as kemuning in the Malay world. It is (or is supposed to come) from the small tree Murraya paniculata (L.) Jack and usually pieces of burl are selected for hilts. I would not be surprised to see some other burl wood utilized, too; kemuning is widely cultivated and relatively available though (despite good pieces getting rarer).
The default identification for the typical wood utilized for the gandar would be angsana, (ang)sena (Pterocarpus indicus Willd.); the nice chatoyance shown in your example is not a defining character - it depends on the individual piece of wood, how it grew, and how it was cut and surface-treated.
I note that in the keris Bugis book, the apparently same wood is referred to as cenrana = sendana (Santalum album L.): This is the well-known sandal wood (non-fragrant sapwood is not rarely utilized on Jawa for this purpose); IMHO this wood looks and ages differently and I believe this is an error.
Regards,
Kai