This ABT Gibbons genuine gearbox formed part of a 1 piece lock which is no longer available. It is also known as the Zenith Staybrite or St Helens glass door lock and was available with concealed shootbolts or as part of a 3 point locking mechanism. None are manufactured any more but the gearbox is normally the part that fails. This version does not have a snib and was commonly used on UPVC doors. Reverse, reinsert and replace screw. Not supplied with faceplate, strike plate or fixings. Brackets are threaded Aluminium version with snib also available.
Latch reversal: Push in latch, undo screw in side of lock case (adjacent to the latch) to remove the latch. Reverse, reinsert and replace screw.