The central locking has packed up on my Disco 1.
I have got the new springs to repair it but not got round to fitting them yet.

I have been locking it on the key, which was very stiff to turn.
On the weekend something gave in the lock and now it won't lock the door.
The key turns freely through 45 degrees either way.

Do I need a new door lock or can this be repaired?

Take the door card off and have a look its the only way you will find out.