rim lock

Just moved in to a new house which has a decent from door lock. https://www.uniononline.co.uk/uk/en/products/locks-and-cylinders/rim-locks/bs3621-cylinder-rim-nightlatch-v-4l67e-b-pl Does anyone have any idea where I would buy replacement cylinders for these? No idea how many people the...

Hi, I currently have a rim lock on our back door that needs replacing. I was planning on fitting a mortise lock but obviously the existing holes for the key and spindle will not line up. Is it better to Install another rim lock or do a mortise and fill the existing holes with some dowel and...