Nill Grips made from Walnut come from Germany, they have an outlet in Bandera Tx. They fit better than any other reproduction grip. They are meant to be fitted by removal of a small amount of wood at the very bottom of each grip so they fit your Luger really tightly.
Here is there website. They tell me that Luger grips are their biggest seller.
CLICK HERE for Nills Luger Grips