Yours looks like the one attached? I don't have a picture of this dissembled I'm afraid.
You have to take off the panel at the back of the back of the boot to access it. The lock and catch mechanism looks like this:
https://www.worthpoint.com/worthoped...atch-161249877
I bought a catch from Bryan Purves -
Home - Bryan Purves - so he may also be able to sell you a new lock?
I don't know without taking it apart whether you can get a new barrel.