in eigens beauftragten Werkstätten

in eigens beauftragten Werkstätten werden die Repliken (dort unter Rückgriff) auf traditionelle Techniken hergestellt.

Results (English) 1:

the replicas (under recourse) on traditional techniques are manufactured in specially authorized workshops.

Results (English) 2:

in specially commissioned workshops replicas are made (there with recourse) on traditional techniques.

Results (English) 3:

in special representative workshops are the replicas (with recourse) to traditional techniques.