The Mg08/15 with the shrapnel damage looks rather familiar. It is like the combat damaged one I used to own up to a few years ago. I removed the barrel and cut the barrel extensions before the barrel was re-inserted and welded back in place. this allowed the whole crank and barrel extensions to be romoved from the receiver - a far better way of deactivation. When I was restoring the gun I found a shrapnel ball embedded in the piston tube inside the barrel jacket. I left it in place. If it is the same gun you may be interested to know it was handed in to the police by the National Trust who found it in the attic of a large country house near York. The barrel was marked 'UNKNOWN' which signifies it was presented to a military museum by the war trophies committee set up after the war.