My front door Chubb mortice lock has been getting hard to work recently & I thought I'd have to replace it. I was looking for the same model so it would fit straight in, otherwise I'd probaby need a lock fitter. It's an old lock & I wasn't sure they still made them the same size etc.
My local lock shop had them for £128 but said it may be repairable & to bring it in. Just did so & they put new mechanism in for £14 - result.