Maintenance/Mouse button replacement

Background and problem

I'm your ordinary sort of office worker, who types and clicks far too often in the course of a day. Various body parts connected to these devices are getting old and very much appreciate that my employer has supplied me with a mid-range ergonomic keyboard and mouse. Office workers of the world, you are advised to ask for at least this much. I think I'm emotionally attached, perhaps it makes me feel fancy that someone spent one hundred euro on me, or one must perform one's longevity once the job becomes a career, like a delivery driver hanging a pair of fuzzy dice over the rear-view mirror after pulling away from headquarters.

The mouse trouble began when I moved into a "home office"—we'll spare most of the details except to say that my standing desk is not much more than a cutting board screwed to the wall at navel height. This is the perfect height for extremely destructive impact of any plastic-encased electronics unlucky enough to fall to the floor, and small enough that this happens often. My mouse has suffered and its once-noble exterior is held together either by gravity or by a small number of the original fasteners. But it still clicks!

At least, it clicks most of the time. Where this inconsistency really starts to burn is double-clicking, which is an ableist-enough exercise under normal circumstances and a fool's errand with iffy buttons. For the past year, I've software-mapped the right and left buttons to switch them, and I hold the mouse in a funny way which lets me imagine that everything is fine, sort of. It's also causing my habits to cross-wire, and anyway I find that the right button becomes increasingly important in proportion to how much I can't use it.

To measure missed clicks, I used trusty xev and it showed that the buttons had become sensitive to the exact orientation of my finger. Either something was wrong with the alignment of the broken plastic parts, contact material was worn off of the internal switch, dust sand and chips had gotten in, or all of the above. I cleaned the button, flooded it with isopropyl, imagined very hard that I had fixed the issue, yet still nothing changed.