Hi Robert,
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The possibly relatively old scabbard might be a plus, whereas the hilt seems really recent to me. How long was this kris with your friend? At least, I'd replace the rattan with a more suitable (and nicer) traditional wrapping! Clamp & ferrule would be fine with me, especially if both were to test positive for silver.
I have mixed feelings with the blade - if pressed hard I'd therefore tend to a conservative guess, i. e. 20c. I agree with Rick that the file work is quite nice. OTOH, the scroll work seems to be a bit shallow (from the pics). The convex side of the first luk could flow nicer and also the engraved lines don't follow the luks perfectly (cp. pic #4). A light cleaning etch to remove the rust would give us probably more clues on the quality of the forging (laminations/tempering).
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I'd concentrate on the blade: if you like it, go for it (regardless of exact age which we'll possibly never know). I understand that this may influence the price you might be willing to pay though...
Regards,
Kai