Hello Jean,
As far as I understand, although these keris are named and dated as keris Majapahit, this must be considered a misconception. Indeed the one found inside one of the stupa op Borobudur (now in the collection of Theo Alkema) might be an indication of when they were made. However, there is no reason why they couldn't have been made earlier or later. Among others, Theo Alkema ( Book: Iron Ancestors) and Martin Kerner (A statistic study on the morphology of keris) come to the same conclusion: There is no certain way of telling how old they might be. When I was at Martin Kerner's home I handled a proto keris ( as depicted on candi Suku). It was dug up from the slopes of the inside Bromo krater. He had this specimen carbon dated. The conclusion was (within a certain time frame), around 800 ad.
The Knaud keris has not been subjected to this kind of testing, there is only a year indication. Apart from these more or less subjective indications, there is no certainty.
When my friend collector and I discussed this, we tried to be open minded and be guided by what we saw’. By looking at the individual keris and by comparing among others, skin, material, wear, weight, figurine posture, tilt, squat, head attire, face, body decorations, one might conclude that one keris is part of a group and the one group could be older than the other. The wear could be a problem. Has this keris, tosan aji, been dug up, been taken care of properly, placed in the stream of a sawa, revered as pusaka? The same approach can be used when looking at the Jimat and Kudi published on the other forum. As indicated earlier, there has already been an extensive discussion and a link to Alan Maisey’s site with lots of information.
http://www.vikingsword.com/vb/showt...highlight=putut