Hi,
I just want to tell you that you have found a fantastic kastane for the price. I have seen examples in much poorer condition go for three times that. Congrats, it's a keeper.
As noted before, these swords were generally not meant for fighting (like many piha kaettas). They were made for people of rank or importance. They were likely inspired by Dutch naval swords during the Dutch colonial era in Ceylon. These swords, as well as the pihas, were not likely produced after the King of Kandy surrendered authority to the British in 1815. These are old swords.
Somewhere I have seen a pic of a painting of "Bonny Prince Charlie" wearing a kastane. If anyone can still find that pic, please post a link!
I've read several historical comments about the fine iron ore found in Ceylon, but the blades produced there are frequently not of a quality that would reflect this. However, the real art was poured into the other aspects, as you can see, and the styles and patterns were very explicitly defined in Sinhalese terminology. The spirals, swirls, and animal forms were heavily inspired by the surrounding flora, fauna, and spiritual beliefs.
This sword is almost certainly not wootz. If anything it would be pattern welded, and may possibly be differentially hardened "like" a japanese sword.
Again, congrats on the find. Let me know if you get tired of looking at it
-d