There is lots of infos about this type. But I think, you mismatch the subtypes a bit. Before 1991 laminated wood was only build in the low budged versions with the suffix 'Exquisit', which differs in even more details from the normal line and parts (as well as the hull) are not exchangable.
So you have in total following versions from before and till 1991:
RZ-85/1 (1954 - 1968)
RZ-85/2 (1969-1972; relativly rare)
RZ-85/3 (1973 - 1991)
RZ-85/1 Exquisit (1963 - 1972)
RZ-85/1 Exquisit-b (1967 - 1971)
RZ-85/2 Exquisit (1967 - 1971)
RZ-85/3 Exquisit (1973 - 1990)
You can check the details on the differences yourself here:
https://typen.faltboot.org/f2104_werft_var.php?ID=10https://typen.faltboot.org/f2104_werft_var.php?ID=27In general you can say, the earliest versions like the normal RZ-85/1 were best in quality (i.e. 5 layers hull), while going on through the 70/80ths the quality fell slowly down and down. The 'Exquisit's (despite that name) where the low budget ones and should be avoided (although lots of them have survived till today).
During GDR times there where a few changings in company structure and names and also some sub-companies (outsourced) like Taucha-Favorit, who build whole boats for Pouch in different locations, so the naming and versions can be confusing sometimes.