... I would presume it to be of later vintage. During the communist era, no ETAs were used, if I am correct. These would have cost hard Western currency, which the government did not permit to spend on things other than pieces of high technology (computers, etc.) that could not be produced indigeneously.
Following the collapse of the German Democratic Republic in 1989, the GUB survived a time of turbulences, during which it was supplied with both, stored own movements, and Swiss 2824s and 7750s.
If your watch has an 2824, I would therefore assume it to be from that time, 1989/90.
Anyway, a very nice watch, I have never seen such a diving watch before! Can you post some more pcitures, please? If possible, from the back and the side.