Not much use without the keep though, I have a complete Chubb Combination latch in near factory condition with original lockout/open pin and keep, the keep forms part of the security features of the lock, The idea was that if someone tried to slip a knife between the door and frame to lift the latch, The blade would lift some of the bolt plates and not others hence the notches cut out of the bolt plates, Also worth a mention are the grooves cut into the bolt plates which function as a false sheer line on the keep, Lifting the bolt plates as well as applying pressure to the door would trap the bolt plates in place preventing further lifting of the bolt, Releasing the pressure on the door will allow the plates to fall back into their resting position.
