Saint Michael's flamboyant sword aside; if you want to see the keris in classic European art check out The Blinding of Samson by Rembrandt.
I understand enthusiasm; but learn more about this weapon form and its meaning within the culture before spending too much hard earned cash.
An educated buyer ends up happier in the long run.
"I read that an odd green color showing in the sunlight is a sign of meteorite. I'll have a good idea when the blade is thoroughly clean."
Well, this is not true; what you have been doing to the blade by cleaning is actually removing the original stain that the blade was given.