Wonderful stuff !
The variable scope from this period is far more complex than the fixed power.
I can dismantle a fixed power scope pretty quickly and without drama but I wouldn't attempt this variable without some training .
I assume the graticule is at the eye piece ( rear end ) so that the variation sleeve is pushed out from the objective end .
For safety of the graticule I assume also that the setting is 1x so that it is retracted