keris information asked

[auk]

Hello to you all and greetings from cold holland

I have a keris that was passing on from my father.
He get it from the neigbours about thirty years ago.

It was full of rust now almost cleaned it and almost all of the rust is gone.
It took me weeks to remove the rust just wit a little tiny brush and some lemmons.my
There is a litle naga on it and under the rust now comes just some little trace of gold plated material on the keris.
Also there is a little golden ball in the mouth of the naga.
Also wat i know is that there is in the waranga a laughing man with a hat on is head and in the hat is a stone.
now you cant see it with your bare eye but when you lay a rice paper on it and gently draw with a pencil over it it apears and you can see him.
Can some one tels me wat it means.
i realy hope some one can give me more information about it, age type ,etcetra.
much greetings Auk