I believe it is a good keris too, detlef. (or should i called u sajen?)
If I was not mistaken, I can see that the blade has been warang / etched / stained. If it was a bugis-riau keris, do it still need the warangan? Didn't by undid the warangan, the pamor can't be seen clearly like this?
What pattern of pamor is that? I think I've seen such pamor in some sumatran kerises, but I dunno what name it goes...
If it was an old keris, it was so lucky to be in right hands, since very little trace of damages can be found there...