I have had some performance issues with the L and R shoulder buttons for SNES controllers.  This design is intended to improve response of these buttons.  

My issues with the original design could be caused by sometimes not pressing directly above where the rubber pad is located along the length of the button.  This would result in needing more or less force to overcome the springiness of the rubber, due to the pivot.   

This is a drop in replacement which replaces the pivoting design with a linear design.  With this linear design, the button presses directly oppose the rubber pad and feels more consistent with each press.

Each set uses a casing that wedges between the shells and a button that fits within it.  This has been tested using ABS and 0.4 nozzle/0.2 layer height.  The casing portion requires supports.