If my memory doesn't fail, the numerous DDR gunmakers were consolidated in the form of a trust, with individual companies remaining more or less autonomious; it was the production of the major parts that was centralized, with most if not all of the barrels made at Sauer, and the actions ar Simson (again, if I'm not mistaken). The variation between guns of the same grade was usually negligeable, but there was some variation of the types of guns made, e.g. Simson made the hunting O/Us, mostly of higher grades, while Merkel made both sports and hunting O/Us. Most smaller firms, like Haenel, were not regarded as highly as Simson/Sauer/Merkel, with the exception of Wolf, and Buchag, the latter generally though of as the "DDR Best".