This looks to be an older MK1. I used one for hunting bear,moose,and deer for years in Maine. Also for tracking wounded bear at night.
These first DE's were built like a tank. The recoil is surprisingly mild because of the weight,gas system,and recoil springs assembly.
This is the cheapest that I have seen one of these at for a long time. If it were at the gun show,it would be gone.
Best of luck with your sale of this weapon sir. Someone will be getting a fine hunting gun. --- SAWMAN