I ran across an old 870 wingmaster 16ga. its a tight gun with a lot of life left in it. I hadve had several offers on it , but I love the way it feels. However, there is a problem, it has a improved cylender fixed choke, and I have had no luck finding another barrel . I was wondering if anybody can help me find someone to put screw-in chokes in it. I know the choke tubes aren't easy to find either. But I sure would love to take the old gun squirrel hunting with my dog, and an IC choke jut wont reach the top of a big ole redoak. thanks in advance for your help.