The early "West German" Diavaris were not heavy, they are quite short and optically superior to most scopes at the time and still optically superior to most scopes today. At that time lead was still being used in the lenses and you can't argue the quality even though the early Diavari scopes are now 30 years old...
I had a 4x version of the same scope and agree they were and are still optically and mechanically superior to most scopes today. They're way better than a Conquest as regards quality. Made in Germany with a 1" tube for the U.S. market. They're also not very heavy.
The main tube with turret housings was machined out of one piece Duralumin. The scopes themselves went through extensive quality control tests. Each scope was given 1,000 shocks simulating twice the recoil level of a .458 Win Mag. Each reticle adjustment was wound to it's extremities 100 times and then tested to see if the P.O.I. had changed. If it had changed the scope didn't pass. Each scope was placed in a vacuum chamber and subjected to a heavy shower of water for 24 hours. A large part of the cost was in the QC. They're superb scopes with good light gathering ability.
