The latest of the Diavaris were made in America, the earliest in "West Germany" and anything after 1990 was made in "Germany". The earliest were with the older leaded glass before the environmental changes with leaded glass. These scopes are very clear and bright, easily ahead of their time in the optical department.
T* and T*P were later changes in the coatings of the lenses, some say that the T*P were best, but the early West German are damn good. Eye relief is short with them but not critical. The compactness of the scope is remarkable and the 36mm will easil out-perform many of 42mm and larger objectives.