Determining age can be a problem; many new keris are artificially aged and sold as antiques .
Your blade appears to come from Madura and may not have a core; hard for me to tell; if there is a core it is thin .
The blade seems to have been given a fairly heavy etching as it appears topographical . I have a similar Madura blade .
Here is that pamor type with a normal etch see pic below .
I don't think that this was done to deceive , rather more for effect .
I believe this is newer work .
Rick
Could I recommend a book or two ?
Garret and Bronwen Solyum .
The World of The Javanese Keris . (Erik's Edge has it)
David van Duuren
The Kris .