[VVV]

Alan,

Oxford University is always a good source for credible references...
Anyway, Scott (who is an esteemed academic historian and not a weapon collector) is translating the 17th descriptions from the Jesuit missionary Acina (and earlier descriptions from other Spanish sources elsewhere in his book) as a kris sword (see my quote).
Other kind of blades he describes as daggers, so he seems to be quite specific on this matter (which of course is very essential for our discussion).
This means that some kind of kris swords existed already when the Spanish arrived to "the kris sword belt" in the 16th C.

To summarize:
a) Spanish sources state that there existed kris swords in the 16th C.
b) Weapon collectors state that some of the kris swords in museums and other collections - among them labelled "the archaic kris" (sword) - were made from the early 18th to the beginning of the 19th C.
c) It is not proven if the "archaic kris" (b), which we know what it looks like, is the same as the 16 - 17th C "kris sword" (a).
However, even if we at the moment do not have a picture here of the kris sword described in Scott's book, this does not imply that there is no proof of the existence of kris swords before the 18th C.

My suggestion as a start is that some forumite who can read Spanish double checks the original sources of Scott's to find out why he considers them to be a kris sword, instead of a kris dagger.
However, Scott is a historian and his publication is following academic standards. This implies that his research and conclusions already have been peer-reviewed by other historians (who probably not were sword collectors and, like you and me, biased in this matter).

Michael

PS If I would have been at home I would have been able to present other historic references than Scott/Acina for kris swords earlier than the 18th C, but this is a good start.