Here is an original complete working 21B  3 slot Pay phone  upper housing lock.  This is a lock that has not been tampered with or molested. Its an original factory lock.

 If you need a  upper lock for your Western Electric, Northern Electric or Automatic Electric 3 slot pay phone this will work well. These will not last long.

Stamped  21B Comes with Key.

We have the screws to mount these locks sold separately.