I typed up a big response to this post last night but for some reason it was deleted when I hit the submit button.

I have been through the lock rebuilding myself and it is not too painful. I'd recommend taking a bundle of digital photos to remind yourself how it all goes back together.

The thing that stumped me is that a previous owner had tried to fit the lock back-plate from a RH door into the LH door lock. In the end I had to machine up a new one from aluminium. You won't find parts like this new so unless you have a parts car nearby you might need to get inventive to repair worn out locks.