Mortice Lock

[jc1985]

Hello. I ordered a replacement mortice lock online for an internal door and clearly didn’t measure it properly as it is not wide enough. I have attached pictures of my current broken mortise door lock and was wondering if this one would be the right size? Apologies if this is a dumb question. Thanks in advance.

 

[JohnD]

It looks like your old one has a three inch case.

You need to measure the exact distance from the centre of the keyhole to the front edge of the faceplate. Compare it to the new one. As it is quite old, it is probably made to imperial measurements, so it will measure to a quarter or eighth of an inch.