Throwing the engine lead switch, there was an unusual “thunk” and then the lever moved a little too easily. Reaching underneath, I felt a new sharp edge rotating behind the fascia. A couple of the levers have needed replacement, but this was the first quadrant that broke.
Fortunately I still have the drawing. The new FDM printer made a part that feels stiffer and stronger than the original, and it only took about 15 minutes! Why would you keep a backup when it takes less time to make one than find the reserve piece?
It’s a brave new world.
Pembroke:87 
Excellent case study. Were you tempted to make any design changes while you had the file up, like making that arm wider at the base, tapering to the pivot hole?
Not especially. The arm shape is constrained by the hole in the fascia and the clearance for the mechanism itself. Monkeying with the design is easy in CAD, but I’m reluctant to reopen the head-scratching behind it!