72v1 CONSTRUCTION OF WEIGHTS

[Searcher]

If there was an attempt to draw a rocker with an arrow and  trunnion in mutually perpendicular planes, then there is no hint of an axis passing through two ears of trunnion on which the rocker should rock.
This can only happen if the artist has never seen the scales (copied from another source) and he raised the ear of the trunnion too high (above the rocker).

Vladimir, this is how I see the construction of the VMs scales (Libra):
   
Likely, the left joint in the VMs Libra is just incorrectly too high, maybe it just was drawn without needed accuracy.