This is the first design of derailleur to be manufactured in the DDR. I came from what had been the Fichtel & Sachs (F&S) factory in Reichenbach, which, I believe, had never manufactured F&S derailleurs. However this FuS design does, naturally, use a lot of small parts that are very similar to those on my F&S 9/a derailleur. It is also constructed and finished to a high standard.
But this is a new design, not a pure copy. For example it has a plain round pulley wheel, with no teeth (which is not F&S’s normal style), and a chain pusher plate (which is also unusual for F&S).
The hanger plate on this derailleur is particularly baroque. In its original form there was a very splendid rubber boot protecting the sliding shaft mechanism. Unfortunately this had rotted to a few wisps by the time I got my hands on it.