FZ-09 Aftermarket Brake and Clutch Lever Insert

I bought a bike recently. One of the previous owners did not like the stock levers and replaced them with these $22 Ali Express ones (I dislike cheap aftermarket levers). The levers are fine but they came partially assembled from the most recent owner (the adjustable extension was unattached, leaving 2-finger shorty levers).
The levers have a dovetailed extension that is anchored with a single hex bolt; the bolt does not strike the red material first, it strikes the grey material first, so even