Hi, recently picked up a universal m1 30 carbine in stainless steel, has SS19XX serial#. it looks to be unfired and in over all really good shape, it came with a stainless 15rnd mag with iver johnson on the bottom plate. I heard that iver johnson had made universals for a short time, is it possible that this was the original mag with the gun? Also any other info, value, fyi's for this rifle would be appreciated. Thanks