Gene, if you could get the surface of blade back to this quality (etch or not to etch is your decision), it would be ideal. You should consider well if it is possible at all without remowing to much material.
http://www.vikingsword.com/vb/showth...=keris+panjang
About age: probably all that you would hear about it were 19. cent. It seems, some greater precision (if it isn't a piece with provenance) is not possible.