Brought the grand total to $30 with yet another new M100.  Big surprise, the new one was nowhere close to the old one with all its modifications & wear.  The new buttons & wheel weren't as loud & didn't travel as far.  The replacement tact buttons in the old one were a big improvement.  Lions just seem to have adapted to longer travel, more resistance, louder clicks.  They might also be making new mice quieter for video conferencing.

MHPS buttons aren't a sure thing anymore.   They might require too much travel for double clicking since they have to fully extend.  The winner might be mechanical keyboard keys or more assertive tact buttons.  Low profile tact buttons just don't last long enough.  The standard mouse button is based on a limit switch, designed for high wear but doesn't travel very far.  All the resistance comes from the tiny limit switch button.

The limit switches would travel more if they still had their levers.  The standard wheel has a lot of resistance from being a mechanically disadvantaged lever.  Ended up stuffing the old electronicals in the new enclosure with the new wheel.

Stiffened the new springs to give the wheel clickiness & resistance.  Added silicone grease to keep it from shedding plastic.  It became clear that the wheel uses a different limit switch with more travel than the buttons.