I definitely prefer the plastic detents, but they do wear after a while and yours does look worn across the top.
I'd start by replacing your detent.
Just got done sending paint through it today , an now its triple feeding , every 4th shot or so , i go back to the bench to look @ it,
and i noticed
I have a set of raw AGD lion panels on my mini-vert frame.
I would really like a set of black panels. They can have a design or not.