I don't have an extra, but they seem to be pretty common on ebay--you can often find a NOS 14-38 for around 20 bucks. Someone on an earlier thread speculated that the same few freewheels go around and around--people buy one, find that they can't make it work, and re-sell it to someone else. The issue is finding a rear derailleur that will go that big. The Duopar works really well, and there's a Suntour model whose name I can't remember that does also--was apparently designed to work with the Suntour freewheel. Others might also work. But you're all set, I think--don't you already have at least one bike set up with a Duopar RD?