I really don't know why ya can't just order one new from ICD, where they'll gladly cocker thread it for you. If anything, the ICD barrel thread pattern isn't too bad in of itself really, being a little quicker to thread than a Cocker thread anyway. I guess you must have a few Cocker barrels laying around for this to be worth mentioning I suppose.
See if you can swap it in at ICD if you already have it, or just get it from them in the first place if you're just thinking of getting one fresh.