Everything that David has written is good advice, however, I would proceed a little differently with the blade, I would take it into the kitchen, along with a hard toothbrush and give it a good scrub under running hot water with some dish was detergent, then I would pat dry with a lint free cloth, and blow dry with a hair dryer or hot air blower.
At that point I would assess it and decide whether it was OK as is, in which case I'd give it a drenching spray with WD40 and let it dry off before painting it with a light machine oil, or medicinal paraffin, preferably scented with sandalwood oil or similar.
If I decided that I might be able to improve the stain, I'd probably start by getting a couple of fresh tahitian limes squeezing & straining and then massaging the lime juice into the blade with a soft toothbrush, as the blade colour came up I'd rinse & dry & repeat. An old half stained blade like this will often respond to a half stain process.
If it is really dirty & corroded after the wash in the kitchen, a soak in white vinegar for a couple of days together with picking away rust mechanically as David suggests could be useful.
There are a lot of different ways to go with a keris blade, and it all depends upon your assessment as to which way might work the best, short of a complete strip back to a white blade, followed by a competent stain with lime juice and either warangan (natural arsenic) or laboratory quality white arsenic --- neither of which I will go on record as recommending.
|