Welcome to the forum Dave,
the wood of the scabbard can need a cleaning with car polish and after this an oiling with a good wood oil. This will prevent that the wood get more cracks like to seen on your pictures. The wood of the cross piece can be kemuning wood but I am not certain by this.
So far I know are Peninsula keris blades are not etched/stained with arsenic solution but a cleaning with an acid like Jean suggested will bring out the pattern on the blade as well.
Nice keris !
Regards,
Detlef