Beseler 45M Support Arm Reversed

The support arm of a Beseler 45M was installed in a reversed position - i.e. the open end that engages the carriage bar was facing upward. This seemed odd - when bumped the thing easily can drop suddenly, and it doesn't stow anywhere as originally attached. I drove out the pin to reverse it so the open end is pointed downward over the carriage arm, per the manual drawing. I have a temporary 'pin' at the moment. In this 'proper' position, the lobe requires force to 'snap' past the carriage arm to engage or disengage. This beast is new to me, and it just seemed odd - is this normal?

 

Is this a brand new unit or used ?

Is this a brand new unit or used ?

It is several decades old - got it second hand. Was in pretty rough shape. The manual's exploded view shows that, at some point, someone had reversed the position. Very hazardous - I was using it in the horizontal position, and a slight bump caused it to drop. It also interfered with raising and lowering the head, as the arm would have to be moved out of the way of the cross supports behind the carriage.

 

I'm simply going to use a smooth pin, with a little cap nut, to put it on or take it off - though would like to see if indeed the arm is supposed to 'snap' into a stowed position.

Thank you for looking

Mark, all looks well aside from the pin coming out. It is the adjustment of the brass fitting that controls the directionality of the light onto the easel. I use this arm all the time to switch to mural size printing on wall.