I had boot lock that would not open, lock rusted and central locking tripped out so had to resort to breaking into via the boot. I was willing to buy a replacement body but looked everywhere for weeks without success. In the end I resorted to getting the lock cleaned via Ultrasonics, and the skills of a watchmaking friend to get it working again.
Is the physical damage terminal? you could try buying a similar lock (with key) and swop the barrell over perhaps? I seem to recall that the lock barrells on the door of a Clk where the same size as that contained in the boot lock. If I get a chance I will fish about in my Clk parts bins to see if I have a spare one, it won't be till the weekend and I won't have a spare key to match but the key thing (no pun intended) will be the size of the barrell if you where up for the swop.