What handle and lock for sliding door with no internal mechanism?
This is somewhat of a tangent, but 1959 is early enough that it's possible that tempered/safety glass wasn't used in the door. (Internet says 1964 is when that requirement went into place in America.) If it's using normal window glass and someone trips and falls through the door, they could be severely injured or die. With that in mind, I recommend checking the corners of the glass insert for any markings like "tempered". If there are no markings, I would recommend at least considering replacement of the whole door.