Derny
Welcome to MBc. I'm sure someone here can help you...I sure can't because I have no earthly idea what a 'derny' is, or even know what one looks like...nor would I know a 'real derny' from a 'fake derny.' I would suggest that you first give us your name, then post your question with a little more info and a picture in the proper forum. Good luck on your derny quest.
Redact: Well I learned something today. Thank You. However, I still don't know where you can get one in the U.S. It seems there are a lot of places in Europe, especially in Belgium, where they were born. I would just keep searching both here and Google. I'd still put your plight and a photo in our forums (Buy/Sell/Trade and/or General Discussion). I'm certain that some of our thousands of members can point you in the right direction. Good Luck.