@guy_27 helped me out with one when mine broke in my Astra a couple of years back. Not sure if he has any more available.
Rather than swapping all the locks around the car I opted instead to just swap the tumblers over from the broken barrel to the replacement. I made a video when I did it if you are interested. It's an easy process and saves having to pull the door and boot locks to swap keys.
https://www.youtube.com/watch?v=Nk477RIrpYw