What you're doing is called "Multilooting." You can get endless goodies that way, as long as you have the patience to keep reloading the savegame until the body does not disappear. It's usually done as a byproduct of "Mephistoing", so named after one of the earliest MM players to have discovered the technique. Basically, he was looking for any of a number of particular treasures, and he was going to reload the savegame until he got one of them. He found, as you have done, that occasionally you can strip the corpse and it doesn't vanish.Carry on, and enjoy yourself! 
