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 has a snib and was commonly used on aluminium doors. Reverse, reinsert and replace screw. Not supplied with strike plate or fixings. Brackets are threaded UPVC version without snib also available.
Latch Reversal: Push in latch, undo screw in side of lock case (adjacent to the latch) to remove the latch. Reverse and reinsert.