Here's some information for you OGB. Others may follow with more.
The hilt, which looks more like bone than ivory to my eye, is a form from East Jawa known as Janggalan.
The blade form (dhapur) of this keris is called Kebo Teki. Kebo blades tend to be good for people who are involved in agricultural endeavors.
I am not sure about the pamor pattern. Looks like it might be one of the adeg (standing) patterns.
I will leave it for others to place this keris in an era. Fair to say it is certainly antique. I like keris to have IMHO. But then, i have a thing for Kebo Keris.
