Thank you for your comments Prostheta !
Yes, I have to do a small groove in the beginning of the headpiece to accommodate a Fender style nut. Tomorrow morning I´ll buy the nut, take measurements and finish the headpiece (polishing, etc, before chromium plate).
Today, I was talking with a friend that has a small lathe in order to make the tuner pegs. Because is impossible to make a centered hole in a brass bar with my drill press.