This might be my best trash pick yet!

When I pulled this from the trash I thought it was an old Shwinn. Then at a closer look I find out it is an old German made bike called a Durkopp. I am still trying to find out the value of it. I am not sure yet what I am going to do with it! All I do know is there are not many of them! can anybody tell me more about this bike. It would be beautiful all cleaned up! Thanks Jackie